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Sheldon believed these physical characteristics also influenced personality. Both male and female progeny show exactly the same phenotypic ratios for characters controlled by autosomal genes. There is a further distinction between interval and ratio level variables. ” If your index finger is 3. The ratio of 4 to 8 to 12 is the continued ratio 4:8:12 We get the continued ratio above by combining 3 ratios. Financial ratios help to provide an economic overview of a business. Speed ratio (i) = z2 / z1 x z4 / z3 = n1 / n2 x n3 / n4 (1. 3 bars per foot; the bars must be spaced not more than 12/2. Listed are the expected RPM's at 60 MPH with a given rear end ratio and tire height. All low voltage protective devices are tested at an X/R ratio. Current Transformer Types. 68) Bronze. 5 the slab is taken as two way and reinforcement must be designed by code method which gives coefficients for long and short span and the bending moments can be calculated depending on if they are fixed on 2 supports or continuous. Compression ratio, blkcnt_uncmp divided by blkcnt_cmp. Both 6 and 9 are divisible by 3. The second category of ratios included in our list of financial ratios is the solvency ratio, which is also the most important financial ratio. Suppose you are a teacher at a university. 5 = 270g flour. 1 inches long and your ring finger is 2. the denominator is the maximum possible value that the numerator can take) can be treated as continuous data. The ratio today is 16:1, much higher than what people are. There are several types of glaucoma. A ratio is a relationship between two values. beer, wine, etc. IAIA x IBi d. Definition: gear ratio n. A type O child must inherit a recessive i allele form the mother and a recessive i. The types of financial analysis are: Horizontal analysis. It is used to measure how efficient and effective are credit policies of a company. Ratio data can be multiplied and divided because not only is the difference between 1 and 2 the same as between 3 and 4, but also that 4 is twice as much as 2. This ratio may be written as 6x:2x:3x where x is a variable. There are three main types of capital structure ratios: Equity Ratio: It indicates the proportion of owners’ funds to the total funds invested in the business. 1 1/2 to 1 3/4 cups of water to 1 cup of uncooked rice. 1 Global Adhesives Revenue 2013-2025 2. When you’re refinancing any type of loan, one of the things a bank or credit union considers is your debt-to-income ratio. This article throws light upon the top three types of control in an organisation. How to Choose Which Type of Graph to Use? When to Use. The Ratio Test can be used on any series, but unfortunately will not always yield a conclusive answer as to whether a series will converge absolutely or diverge. Here is a list of the ratios we use most frequently: Absolute Liquid Ratio is the relationship between absolute liquid, or super quick current assets, and liabilities. More specifically, Collagen III can be present anywhere from 5% to 20% in normal skin, that level would be higher in a newly formed scar. 0:1 would be to have your own unit rebuilt by a steering box rebuilding specialist. We compared 7-Zip with WinRAR 5. These are fundamental rhetorical strategies for the manipulation and variation of discourse across a vast array of linguistic levels: word forms, sentences, paragraphs, entire texts or speeches, etc. The more water used will result in a softer. Ratio analysis is used to evaluate various aspects of a company's. Best Answer: well all you have to do is find the ration of 24 ginger bread men over 16 ginger bread men. Again, the neutron to proton ratio increases. IAIA x IBi d. 5, so you'd drag the slider to 150. Fixed ratio combinations. A pulley consists of a rope and a hub or "drum" in which there is a grooved wheel mounted with an axle. Gas to Oil Pre-Mix Ratios for Two Stroke Engines USA Mixtures Ounces of Oil to Gallons of Gas To Use: Pick your ratio, pick the amount of gas you want to use and follow the columns and rows to the correct amount of oil. The sides of the right-angled triangle are given. Gear Types and Gear Ratios What are gears used for? Gears play a huge role in much of the technology around today. Now, does that make sense?. accounting ratios: Three basic types of accounting ratios are: (1) Efficiency Ratios, (2) Profitability ratios, and (3) Solvency ratios. In this annual report, now in its 30th year, we provide IT budgetary benchmarks and IT staffing metrics by industry sector and organizational size for private and public companies and for governmental organizations, based on our. If the ratio of the number of white eggs to the number of brown eggs is 2/3, each of the following could be the number of eggs in the basket EXCEPT: 10 12 15 30 60 I answered 10 thinking that 2/3 * (answer) should give an integer. Both 6 and 9 are divisible by 3. Profitability Ratios 2. Multiplying or dividing all terms in a ratio by the same number creates a ratio with the same proportions as the original, so, to scale your ratio, multiply or. 4) Sub- Triplicate ratio: It is the ratio between cube roots of two numbers. It may be expressed as a percentage and it reveals the amount of sales required to cover the cost of goods sold plus operating expenses. Profitability ratios 5. The ratios that we'll look at are the current, quick and cash ratios and we will also. Trigonometric ratios provide relationships between the sides and angles of a right angle triangle. There are three types of age dependency ratio. Isolate variable x. Some frequently used long-term solvency ratios are given below: Debt to equity ratio. 3 (30%) Impact Ratio. Also, I'm a little confused where the ratios come in. There are several advertisers. The MarketWatch News Department was not involved in the creation of this content. From LearnZillion. Liquidity ratios 2. Blue mass-to-light ratios within the Holmberg radius versus morphological type. The types are: 1. Take note that most of the ratios can also be expressed in percentage by multiplying the decimal number by 100%. The old school of the law believed that more equity is safe for the firm and there should be more weight of equity in the total capital. To Cook: Add 2 cups water or vegetable broth to 1 cup black rice, bring to a boil, then simmer for 35 minutes; Amount after cooking: 3 cups. The level and type of pain you are experiencing is going to play a key role in determining what ratio is going to be best to use. One common type of problem that employs ratios may involve using ratios to scale up or down the two numbers in proportion to each other. Mainly there are three types of mortar mixes used in the masonry construction. Leverage ratios examine two types of leverage: financial leverage (or whether and how much debt and equity are used to finance assets) and operational leverage (the extent to which an organization's operations involve fixed rather than variable costs). For example. His unit rate is 2 words per second. CD8 cells can kill cancer cells and other invaders. We’ll use a succession of golden ratios to create a golden ruler to understand design in the face: The head forms a golden rectangle with the …. In the language of percent, we say that 6 people are 50% of 12 people. 3/10/08) EPO NO. Financial ratios are a valuable and easy way to interpret the numbers found in statements. The second is an overdrive-- the output speed is faster than the input speed. For instance, in finance it is common to use the earnings per share, gross profit margin, return on assets, and inventory turnover ratios. These different types are arranged roughly in spectral order starting with infrared and ending with blue and UV and then pink. There are several advertisers. If you have a Ford type unit, you could interchange between the 16. 911 ROW 1975. It is used as supplementary to the current ratio. The CNG / FFV fuel type engines are from the natural gas / propane powered engines. More specifically, Collagen III can be present anywhere from 5% to 20% in normal skin, that level would be higher in a newly formed scar. Types of ratios in math. 32 per kg are mixed together to be sold at Rs. Other examples of ratio variables include height, mass, distance and many more. Profitability Ratios: The main objective of any organization is to earn profit. percentages and ratios Percentages or ratios summarise two pieces of information, namely their constituent numerator and denominator values. The old school of the law believed that more equity is safe for the firm and there should. In general, financial ratios can be broken down into four main categories: 1. This ratio can be expressed as the number of gear teeth divided by the number of pinion teeth. Daiwa LEXA-WN400H Lexa Type WN Casting Reel, 400, 6. The lower omega-6/omega-3 ratio in women with breast cancer was associated with decreased risk. The first is the manual transmission. One ratio is used for one particular purpose and helps the analyst to take decisions in future. Accounting ratios are useful for understanding the financial position of the company. Nominal mix ratios for concrete are 1:2:4 for M15, 1:1. There are different types of financial ratios used to analyze financial performance: profitability ratios, liquidity ratios, activity ratios, leverage ratios and market ratios. With 3:1 ratios there are three progeny with the dominant phenotype for every one (on average) with the recessive phenotype. aspect ratios between dimensions mo ij Ii j jk k jl l8 jk jljkj123 kll J x Type -2:accurate formulation, but higher computational cost in explicit Type -1:efficient formulation CPU cost compared to type 2: ~1. A financial ratio is a mathematical expression demonstrating a relationship between two independent or related accounting figures. Single-plate clutch. To find an equal ratio, you can either multiply or divide each term in the ratio by the same number (but not zero). For example Debt ratio, it is used to know how much debt is there in total capital employed. 1 inches long and your ring finger is 2. Alligation or Mixture Questions & Answers : The cost of Type 1 rice is Rs. Most marine requirements, such as personal water craft (PWC), jet skis and outboards,. 5 Types of Ratios. Type-token ratio of speech. For example: 2:3 aspect ratio: 3 ÷ 2 = 1. The most common profitability ratios include; gross profit margin ratio, net profit margin ratio, return on total assets ratio, and return on equity ratio. Ratio = Figure 1. 3 Global Adhesives Capacity 2013-2025 2. Quick ratio is also known as liquid ratio or acid test ratio. There’s a wide world of thoughts on which macronutrient ratio is best, so we narrowed it down to the three most popular approaches: The Zone Diet, Lean Mass, and Body Type. Notes: The 360 HP / 380 HP engines are in the SVT Lightning. Definition: gear ratio n. There are three different forms. 2 Al( s) + Fe 2 O 3 ( s ) Al 2 O 3 ( s) + 2 Fe( l) Because so many reactions occur when solutions of two substances dissolved in water are mixed, a special symbol, aq , is used to describe these aqueous solutions. Speed ratio (i) = z2 / z1 x z4 / z3 = n1 / n2 x n3 / n4 (1. Updated 6/26/2006. Note that neither of these are equal to the gear ratio for the entire train, 4. To explain ratios, draw a set of 3 triangles and 4 squares. 33:1) is an aspect ratio with a width of 4 units and height of 3. If the difference between the prices of costliest and the cheapest cars is Rs. 2 Global High Voltage System Market Concentration Ratio 3. Whatever we choose to compare can then be written as a ratio. Ratios are common descriptive measures, used in all fields. Types of Financial Ratios Financial ratios are the ratios that are used to analyze the financial statements of the company to evaluate performance where these ratios are applied according to the results required and these ratios are divided into five broad categories which are liquidity ratios, leverage financial ratios, efficiency ratio, profitability ratios, and market value ratios. Compare ratios and evaluate as true or false to answer whether ratios or fractions are equivalent. Here are three financial ratios that are based solely on current asset and current liability amounts appearing on a company's balance sheet: Four financial ratios relate balance sheet amounts for Accounts Receivable and Inventory to income statement amounts. While all lenders have their own standards, a debt-to-income ratio of 40. Profitability Ratios 2. Don’t Memorise brings learning to life through its captivating FREE educational videos. Investors use different ratios to boil that information down into usable chunks to make sound investment decisions. Thus, a ratio is a general term independent of a unit and we use it across multiple platforms. The Magic Ratio to a Healthy Relationship relationships Does it ever feel like your partner only criticizes you? Can you remember the last time your partner said something positive to you? When negative interactions outweigh the positive ones, it may be hard to recall the positive qualities in an intimate relationship or in your partner. It is used to measure how efficient and effective are credit policies of a company. Three types of wheat of Rs. It can help you both offensively, looking for opportunities, and. Notes: Reserve requirements must be satisfied by holding vault cash and, if vault cash is insufficient, also by a deposit maintained with a Federal Reserve Bank. Discuss the map ratio which is the scale of the map. We must keep in mind that the accuracy ratings are based on rated primary current flowing and per ANSI standards may be doubled (0. For example Debt ratio, it is used to know how much debt is there in total capital employed. Profitability Ratios. Video of the Day. Mainly there are three types of mortar mixes used in the masonry construction. For example, in the solved example that we solved above resulted in a commensurate ratio 2:3. 18 Because we do not have fractional boots, x = 2. A shareholder ratio describes the company's financial condition in terms of amounts per. 2 Global High Voltage System Market Concentration Ratio 3. Currently there is a great deal of research involving the determination of the ratios of cone types and their arrangement in the retina. There are mainly 4 different types of accounting ratios to perform a financial statement analysis; Liquidity Ratios, Solvency Ratios, Activity Ratios and Profitability Ratios. The quick ratio (sometimes called the acid-test) is similar to the current ratio. In fact, in most cases, analysts and associates will spend as much time performing this task as any other. Click on the Calculate button to find out how many US ounces of specified two cycle oil (or whatever the oil type requirement is for your engine) are required. Let's start with the three types of cash flow in the cash flow statement:. An insulin-to-carb ratio allows you to easily figure out how much of your fast-acting insulin is needed for the amount of carbohydrate you consume. A type O child must inherit a recessive i allele form the mother and a recessive i. 2 Executive Summary 2. Profitability ratios 5. For example, the default figures in the chart are for a stock ratio transmission as fitted to a Type 1, 1303S (3. Ratio features a dense optical array which provides reduced pixilation and increased visual comfort without compromising performance. The gear ratio of the first pair is 3:1, and so is the ratio of the second pair. 7 percent slow to 46. Join 1000s of fellow Business teachers and students all getting the tutor2u Business team's latest resources and support delivered fresh in their inbox every morning. In fact, artists and sculptors have known about the golden ratio for a long time and have used it to create sculptures and artwork of the ideal. Superior efficacy with a fixed‐ratio combination of insulin degludec and liraglutide (IDegLira) compared with insulin degludec and liraglutide in insulin‐naïve Japanese patients with type 2 diabetes in a phase 3, open‐label, randomized trial. 12 July 2018 3. Ratio Scale Data Levels of Measurement. The debt ratio shows how well a company can pay their liabilities with their assets. Nine will have at least one gene for both dominate. Therefore, Liv receives £150,000 and Laura receives £200,000. From LearnZillion. Industry ratio analysis - 5-year. Ratio analysis is used to evaluate various aspects of a company’s. CRISS-CROSS GRID: a criss-cross grid has two. 4:3 was the aspect ratio used for 35 mm films in the silent era. Ambiguities in classifying a type of variable. For the lowest calorie wine type wine. Both of these common alloys are suitable for common electronics, but 63/37 is a eutectic alloy, which means that it has a sharp transition between liquid and. caring for 4-6 (plus 6 SAC) children are required. A mole ratio is the ratio between the amounts in moles of any two compounds involved in a chemical reaction. Liquidity ratios measure the extent to which the. Step 2: Solve the equation. The quick ratio is more stringent, because it does not count inventory as part of the firm's. essential and valuable. A proof of the Ratio Test is also given. Given four possible gamete types in each parent, there are 4 x 4 = 16 possible F 2 combinations, and the probability of any particular dihybrid type is 1/4 x 1/4 = 1/16. Proportions are simple mathematical tools that use ratios to express the relation between multiple quantities. The old school of the law believed that more equity is safe for the firm and there should. A ratio says how much of one thing there is compared to another thing. The collagen I/III ratio will be lower in wounds as compared to "normal" skin (i. gear code is circled in white and is G662, indicating 3. – Use the most appropriate cell type in any combination. AF 33(038)-20840 RDO No. Unlike liquidity ratios that are concerned with short-term assets and liabilities, financial leverage ratios measure the extent to which the firm is using long term debt. Don’t assume that if one side of a triangle is, say, twice as long as another side that the angles opposite those sides are also in a 2:1 ratio. Different Types of Cash Flow. 83 (18/33) 3rd gear: 1. The Magic Ratio to a Healthy Relationship relationships Does it ever feel like your partner only criticizes you? Can you remember the last time your partner said something positive to you? When negative interactions outweigh the positive ones, it may be hard to recall the positive qualities in an intimate relationship or in your partner. These variants are predicted to alter the expression and structure of. With a new spin on a classic rectilinear form, Ratio brings the traditional shoebox aesthetic into the next generation of LED lighting. The more types there are in comparison to the number of tokens, then the more varied is the vocabulary, i. The velocity ratio and train value of gear train: Velocity ratio or speed ratio. Assorted packing or Ratio packing: 4. For instance, if you have a $1,500 monthly mortgage,$200 car payment and pay $300 a month for credit cards and other bills, your monthly debt is$2,000. Fixed Ratio Schedule. List of Financial Ratios. Definition: gear ratio n. Whatever we choose to compare can then be written as a ratio. In an investigation into the language developmen otf 480 children between the age osf three and eight, Templin (1957) compare the totas l numbe orf different words (types in) 50 consecutive utterances with the total number of words in the same 50 utterances (tokens). We have 9 liquidity ratios namely 1. It is for standard television and has been in use since the invention of moving picture cameras and many computer monitors used to employ the same aspect ratio. As, compound ratio of m : n and p : q is mp : nq. Area Ratio Calculator. 3:2 aspect ratio: 2 ÷ 3 =. There are two types of data: qualitative and quantitative. 42:1 Ring and Pinion Ratio and get Free Shipping on Orders Over $99 at Summit Racing! Differential Case Design Type. Profitability Ratio Definition. Enter the number of US gallons of gas added to the tank; the default is 5 gallons. Besides, the type with a manual transmission have the different cams, titanium valves, compression ratio was increased up to 11. The ratio between what you have studied and the total syllabus is 3 : 4. Last week, she treated 12 cows and 16. Ratio data can be multiplied and divided because not only is the difference between 1 and 2 the same as between 3 and 4, but also that 4 is twice as much as 2. 5 Main Types of Ratio Analysis. A profitability ratio is a measure of profitability, which is a way to measure a company's performance. You can see there are four different types of measurement scales (nominal, ordinal, interval and ratio). The three main types of mutual fund expenses. 0:1 units (4-5/8 turns to lock), if the shaft diameters are also the same; however, the only way to change to a ratio smaller than 16. Financial statements provide a picture of the performance, financial position , and cash flows of a business. Both give an average price of 1. asked by Ne Ne on November 20, 2015; Math. A man with O type blood marries a woman with AB type blood. When you’re refinancing any type of loan, one of the things a bank or credit union considers is your debt-to-income ratio. Only with double recessives will the phenotype show both recessives. 12 July 2018 3. As we saw earlier, there are four different 3D element types — tets, bricks, prisms, and pyramids: These four elements can be used, in various combinations, to mesh any 3D model. The only difference between the ratio variable and interval variable is that the ratio variable already has a zero value. Profitability ratios 5. The ventilation-perfusion ratio is exactly what you think it should be - the ratio between the amount of air getting to the alveoli (the alveolar ventilation, V, in ml/min) and the amount of blood being sent to the lungs (the cardiac output or Q - also in ml/min). What are Financial Ratios? Financial ratios are created with the use of numerical values taken from financial statements Three Financial Statements The three financial statements are the income statement, the balance sheet, and the statement of cash flows. In order to calculate the metric, you would simply sum up the number of units of item produced…. So we could also say that the ratio of apples to oranges is 2 to 3. Write ratios as equivalent ratios where the parts that doesn't change are the same. In what ratio should this wheat be mixed? a) 1 : 2 : 3 b) 2 : 2 : 3 c) 2 : 3 : 1 d) 1 : 1 : 2. Consider the following example -. Types of Solder Solder is available in a number of diameters, with 0. F-test or Variance Ratio Test 3. Three possible ratios are 4 : 6 : 8 or 2 : 3 : 4 or 6 : 9 : 12 The ratio 4:6:8 is represented by counting all the tiles. Financial ratios can be classified into ratios that measure: (1) profitability, (2) liquidity, (3) management efficiency, (4) leverage, and (5) valuation & growth. A special cereal mixture contains rice, wheat and corn in the ratio of 2:3:5. 667, so you'd type in 66. 46 times for every time the output rotates once. Ratio analysis is used to evaluate various aspects of a company’s. In simple terms the aspect ratio refers to the shape of your television screen (square or rectangular)? Traditionally, televisions have been made in a square shape called a 4:3 or 1. Staff in Texas State: Must be at least 18 years old and have a high school diploma or equivalent. Aspect ratio is the ratio of the width of an image to the height of the image. A profitability ratio is a measure of profitability, which is a way to measure a company's performance. Ratios may be computed for each year's financial data and the analyst examines the relationship between the findings, finding the business trends over a number of years. Daiwa LEXA-WN400H Lexa Type WN Casting Reel, 400, 6. The heterozygote shows the dominant phenotype. The more types there are in comparison to the number of tokens, then the more varied is the vocabulary, i. Understanding the different types of questions You will need to understand the different types of data to know how to provide the best analysis of the information. The high account receivable turnover ratio is recommended and it is calculated by using formula hereunder:. When smaller changes exist, line graphs are better to use than bar graphs. Reasoning with ratios (6th grade) Understand rates as a type of ratio. 3:2 aspect ratio: 2 ÷ 3 =. Most marine requirements, such as personal water craft (PWC), jet skis and outboards,. The interactions of the two genes which control comb type was revealed because we could identify and recognize the 9:3:3:1. Examples of aspect ratios. 1, which is suitable for many types of fishing. In statistics, there are four data measurement scales: nominal, ordinal, interval and ratio. Financial ratios can be broadly classified into liquidity ratios, solvency ratios, profitability ratios and efficiency ratios (also called activity ratios or asset utilization ratios). The golden proportion can be found throughout the human body. Levels of type I and III collagen as well as the ratio of type I/III were determined by immunohistochemistry and image analysis. Notes: Reserve requirements must be satisfied by holding vault cash and, if vault cash is insufficient, also by a deposit maintained with a Federal Reserve Bank. The biggest difference between each ratio is the type of assets used in the calculation. 3 Global High Voltage System Market Share by Company Type (Tier 1, Tier 2 and Tier 3) 3. In this type of contract, the seller bears the risk. Manufactured by Porsche (ZF) Plate-type limited-slip differential available. No fair peeking at the answers. Most marine requirements, such as personal water craft (PWC), jet skis and outboards,. Similarly, the ratio of lemons to oranges is 6∶8 (or 3∶4) and the ratio of oranges to the total amount of fruit is 8∶14 (or 4∶7). Ratios are great tools …. Multiplying or dividing all terms in a ratio by the same number creates a ratio with the same proportions as the original, so, to scale your ratio, multiply or. Ratios are common descriptive measures, used in all fields. Financial ratios help to provide an economic overview of a business. No inspections are conducted and there are no standards to meet. These are marked by an increase of intraocular pressure (IOP), or pressure inside the eye. A ratio is a relationship between two values. The human face abounds with examples of the Golden Ratio, also known as the Golden Section or Divine Proportion. Next, have the students explain what that ratio means. The valves are similar because of their applying with the 3S-GE Gen 1-3 engine. IAIA x IAi e. Similarly, the ratio of lemons to oranges is 6∶8 (or 3∶4) and the ratio of oranges to the total amount of fruit is 8∶14 (or 4∶7). Indicates a 1 x 1 aspect ratio. When connecting single-phase transformers in three-phase banks, proper impedance matching becomes even more critical. Basing on your blood test results, it calculates the most popular cholesterol indicators (LDL/HDL, triglycerides/HDL, and total cholesterol/HDL ratio), making it easy to assess heart disease risks and your general health condition. Device Type Test X/R Ratio Test Power Factor. A planetary gearbox works relatively the same. This trial investigated the contribution of the liraglutide component of IDegLira versus IDeg alone on efficacy and safety in patients with type 2 diabetes. GM uses the same type 4-digit ID method of identifying FWD torque converters as with the RWD units, however the digits have different meanings. Age dependency ratio (% of working-age population) | Data. DIDDT1_AspectRatio_4x3: Indicates a 4 x 3 aspect ratio. Don’t assume that if one side of a triangle is, say, twice as long as another side that the angles opposite those sides are also in a 2:1 ratio. Lighting Ratios In Practice. RPM - Rear End Ratio Chart: The chart below may be of some help in deciding what rear end ratio is right for you. Two types of ratio reinforcement schedules may be used: fixed and variable. It is a comparison of the size of one number to the size of another number. That amount is usually an added number, such as 4 gallons, 5 gallons, 10. To create an exact aspect ratio, divide the height by the width. The higher the ratio is, the easier it is for the drive axle to turn the wheels. Whether it is part-to-part ratios, part-to-whole ratios, identifying parts from the whole, or finding the whole from the parts, dividing quantities, generating equivalent ratios, or expressing the ratio in three different ways, that you are looking for, these pdfs have them all covered for your grade 5 through grade 8 learners. Thank you for reading this CFI guide to types of financial analysis. Unlike liquidity ratios that are concerned with short-term assets and liabilities, financial leverage ratios measure the extent to which the firm is using long term debt. The number notation of the ratio A to B is A:B; A ratio is written with a colon between the two quantities that are being compared. Unit Rate: Unit rate is a rate in which the second term is 1. Leverage ratios show how much debt a company acquired. Modified Aspect Ratio is a home cinema term for the aspect ratio or dimensions in which a film was modified to fit a specific type of screen, as opposed to original aspect ratio. Day nurseries operate all year round, usually with the exception of bank. Pixel aspect ratio describes the ratio of width to height of a single pixel in a frame. Most soils are made up of a combination of sand, silt and clay particles. Or if we want to use this notation, 2 to 3. " Each category is distinguished by the. Financial ratios help to provide an economic overview of a business. 2 (type -1), ~4 (type -2). The process in which a sample dissolves in water will be indicated by equations such as the following. String describing the compression type. Four Types of Measurement Scales Nominal Ordinal Interval Ratio • The scales are distinguished on the relationships assumed to exist between objects having different scale values • The four scale types are ordered in that all later scales have all the properties of earlier scales— plus additional properties. To compare multiple ratios see our Ratio Calculator. With 3:1 ratios there are three progeny with the dominant phenotype for every one (on average) with the recessive phenotype. Fraction - It is when a ratio is expressed in a fraction, example 2/3 or 0. 5 appendages on each of these, in the fingers and toes. firm’s financial solvency vis-à-vis the current ratio. Each of them was used on different model Land Rovers for different purposes and they are easily identified by looking at the outer differential casing shape. component. Definition Of Rate. Your muscles consist of three types of muscle fibers: slow oxidative fibers, fast oxidative gylolytic fibers and fast glycolytic fibers. It is used to measure how efficient and effective are credit policies of a company. Truss types and node labeling for Pratt and Warren trusses (loads, not shown, are assumed to be uniformly distributed over the floor or roof and applied at the bar joints of the top truss chord) Truss type: Warren Truss type: Pratt. So if you divide 6 and 9 both by 3. This study investigated the alternate forms reliability of four type-token ratios (TTRs) of oral language samples obtained from 52 elementary school children (9 through 12 years of age). Standards 6. 00-02 Jaguar S-Type Rear Diff. There are many different ratios that correctly represent the ratio of reds to yellows to greens. It appears as if the problem with low ratios of omega-3 to omega-6 is the lack of omega-3, not so much the omega-6. First, get to know the most common fund types—money market, bond, balanced, stock, international, and sector—and how they can be combined to create a well-balanced portfolio. Activity: These ratios demonstrate how efficiently the business operates. Here is a list of various financial ratios. SSyy x ssYY. If you have a Ford type unit, you could interchange between the 16. 7) f 3, t 3 =. For instance, if you have a$1,500 monthly mortgage, $200 car payment and pay$300 a month for credit cards and other bills, your monthly debt is $2,000. These three core statements are intricately to gain meaningful information about a company. Find missing values in ratio problems using a table. For example, Jake types 10 words in 5 seconds. What is the general purpose of liquidity ratios? Define the three major types of liquidity ratios. For example, a firm with assets of$1,000,000 and $150,000 in short-term debts and$300,000 in long-term debts has a debt ratio of $450,000 /$1,000,000 or 45%. If both Type 1 and Type 2 are mixed in the ratio of 2 : 3, then the price pe. It is used to measure how efficient and effective are credit policies of a company. Multiplying or dividing all terms in a ratio by the same number creates a ratio with the same proportions as the original, so, to scale your ratio, multiply or. Learn how HDL, LDL, total cholesterol, triglycerides, and heart disease are linked. Quick ratio is also known as liquid ratio or acid test ratio. Genotype: The letters that make up the individual. 911 ROW 1975. The numbers in a ratio may be quantities of any kind, such as counts of people or objects, or such as measurements of lengths, weights, time, etc. However, although it is used to test the short-term solvency or liquidity position of the firm, it is a more stringent measure of liquidity than the current ratio. The current ratio is calculated by simply dividing current assets by current liabilities. For example, organic matter formed in different provenances can be combined, such as when planktonic algal material falls into sediments containing transported woody macerals (kerogen type III). Your ratio may be the same or different at each meal. 1 ) The efficiency ofthe engine is a strong function ofthe compression ratio. Don’t assume that if one side of a triangle is, say, twice as long as another side that the angles opposite those sides are also in a 2:1 ratio. By the time the rice has completed cooking, the water should be completely absorbed into the rice. So we could also say that the ratio of apples to oranges is 2 to 3. Financial leverage ratios provide an indication of the long-term solvency of the firm. Your ratio can only be so big before you start to hit some diminishing returns. The types are: 1. (e) Ratios help in comparisons of a firm’s results over a number of accounting periods as well as with other business enterprises. • Triangles and quadrilaterals in 2D. 88 (8:31) 915/43. RESEARCH DESIGN AND METHODS In a 26-week, double-blind trial, patients with type 2 diabetes (A1C 7. When you invest in a mutual fund, there are three main expenses you may have to pay. The collagen I/III ratio will be lower in wounds as compared to "normal" skin (i. The three main categories of. Odds Ratio It is defined as the ratio of the odds of an event occurring in one group to the odds of it occurring in another group or to a sample-based estimate of that ratio= [A/(1-A)]/[B/(1-B)]. Keep in mind that it is best to use a carrier oil that is 100 percent pure. ssYY x ssyy. Ratio Scale Variables on a ratio scale have a meaningful zero point. (e) Ratios help in comparisons of a firm’s results over a number of accounting periods as well as with other business enterprises. The last year's price/earnings ratio (P/E ratio) would be actual, while current year and forward year price/earnings ratio (P/E ratio) would be estimates, but in each case, the "P" in the equation is the current price. Profitability Ratios. A new 1:3 CL-20 (2,4,6,8,10,12-hexanitrohexaazaisowurtzitane)/4,5-MDNI (1-methyl-4,5-dinitroimidazole) cocrystal (1) in combination with the previously reported 1:1 CL-20/4,5-MDNI cocrystal (2) together have been first realized in different stoichiometric ratios based on CL-20 and 4,5-MDNI in energetic–energetic cocrystals. Activity Ratios. When making modifications or upgrades to your vehicle, knowing the gear ratio can help you to make a knowledgeable decision. ) is bigger than the driven gear, the latter will turn more quickly, and vice versa. The simplified ratio also tells us that, in any representative set of seven people (3 + 4 = 7) from this group, three will. Profitability is simply the capacity to make a profit, and a. So if your index finger is 2. Premium fuel WILL NOT help clean out your engine. In epidemiology, ratios are used as both descriptive measures and as analytic tools. The old school of the law believed that more equity is safe for the firm and there should. You will find easy to understand lessons and tutorials on the topic of market research, along with a variety of market research tools and resources. For example, the ratio of 2 to 5 is written as 2:5. The quick ratio (sometimes called the acid-test) is similar to the current ratio. Here are some common aspect ratios and what they look like. Our prevalence ratio, considering whether diabetes is a risk factor for coronary heart disease is 12. Related Calculators. This diagram was produced based on histological sections from a human eye to determine the density of the cones. ssYY x ssyy. (For 2D models, you have triangular and quadrilateral elements available. Some common unit rates are miles (or kilometers) per hour, cost per item, earnings per week, etc. You may need to experiment to find the consistency you like. the explanations below discuss the models of Land Rovers that used these diffs, what. For 1 gallon at 20 to 1, follow the 1 gallon column down to the 20 to 1 row and you find you will need 6. Note that neither of these are equal to the gear ratio for the entire train, 4. In the true sense, explanatory footnotes should also be called as financial statements. This chart is particularly useful when used in conjunction with an engine’s power and torque data – showing what the rpm drop is in each gear when shifted at a specific engine rpm. Three-way catalysts are effective when the engine is operated within a narrow band of air-fuel ratios near stoichiometry, such that the exhaust gas oscillates between rich (excess fuel) and lean (excess oxygen) conditions. – Can be non-conformal: grids lines don’t need to match at block boundaries. 7–16]) were consecutively included in the study. 3 bars per foot; the bars must be spaced not more than 12/2. benchmarking. Odds Ratio It is defined as the ratio of the odds of an event occurring in one group to the odds of it occurring in another group or to a sample-based estimate of that ratio= [A/(1-A)]/[B/(1-B)]. Gear Ratio’s can be difficult to understand, but with a fairly brief explanation I will attempt to make this often misunderstood equation VERY easy to grasp. Plus, lay a Golden Ratio over the small eagle and it also fits within the proportions. Data types •Data dimension: Point, Line, Area, Volume (Text) •Data continuity: Discrete, Point, Polygon: Continuous •Stevens data level: Nominal, Ordinal, Interval, Ratio •Often involve classification and normalization before suitable for mapping •E. We reserve the right to replace failed parts with equal to or greater than original mileage parts. The ratio today is 16:1, much higher than what people are. If it takes approximately 2-3/4 input shaft turns then the trans is a Wide ratio (2. Total boots sold = 6*2 + 2*2 + 3*2 = 12 + 4 + 6 = 22 Answer: 22. coupe Fifth digit is engine code: D = 250ci, H = 350ci 2bbl, K = 350ci 4bbl, L = 350ci 4bbl, T = 350ci (Z28) Sixth digit is model year: 4 = 1974. Liquidity Ratios: Liquidity ratios reflect the firm’s ability to meet scheduled short-term obligations. The second is an overdrive -- the output speed is faster than the input speed. Join 1000s of fellow Business teachers and students all getting the tutor2u Business team's latest resources and support delivered fresh in their inbox every morning. Gear ratios and compound gear ratios Working out simple gear ratios (two gears) A feature often requested in my gear program is that it should calculate and display the gear ratio. The golden proportion can be found throughout the human body. You can see that when both the dominant (B) and recessive (b) alleles are present in the offspring (Bb), the flowers are purple. so all you have to do now is take each ingredient and times it by 1. For instance, if you have a $1,500 monthly mortgage,$200 car payment and pay $300 a month for credit cards and other bills, your monthly debt is$2,000. An ordinal scale does not have a true zero,. Profitability is simply the capacity to make a profit, and a. The type-token ratios of two real world examples are calculated and interpreted. Another way to think of this is that 1 part in the ratio is worth £50,000, so since Liv and Laura have 3 and 4 parts in the ratio respectively, we need to multiply £50,000 by 3 and then 4 to get their respective winnings. A longer ring finger compared to your index finger is considered a “low 2D:4D ratio. Described briefly, the three body types cited were the thin (ectomorphs), the fat (endomorphs), and the muscular (mesomorphs). Cross sectional & time series. In the 1940s, Stanley Smith Stevens introduced four scales of measurement: nominal, ordinal, interval, and ratio. Liquidity ratios measure a company's ability to pay debt obligations and its margin of safety through the calculation of metrics including the current ratio , quick ratio and operating cash flow. A can express itself only in the presence of ‘B’ or b allele. Liquidity Ratios. Pupil: teacher ratios in the local authority maintained sector (nursery, primary, secondary and special schools) and independent schools. It is the application arithemetic on financial information that is contained in the annual report of a. Overall Pressure Ratio at Maximum Power: 32. Coverage Ratios 3. 88 ring and pinion). 667, so you'd type in 66. Activity: These ratios demonstrate how efficiently the business operates. 1 1/2 to 1 3/4 cups of water to 1 cup of uncooked rice. Eurocurrency liabilities. The video beautifully explains what is the meaning of the ratio, various advantages of using a ratio and highlighting different types of ratios - L - Liquidity ratio S- Solvency ratio. Open-angle glaucoma, the most common form of glaucoma, accounting for at least 90% of all glaucoma cases:. There are three distinct numeric types: integers, floating point numbers, and complex numbers. Three different type of users of ratio analysis are 1) Analyst who study ratios such as gross margin and net margin and return on equity to build view the full answer. A type O child must inherit a recessive i allele form the mother and a recessive i. 59 l/100 km, the urban fuel consumption is 11. First, a Type III estimable function is defined for an effect of interest in exactly the same way as in PROC GLM. The pulley has a wide range of applications in many circumstances and can be used to make a variety of moving and lifting tasks easier. a window CT has a ratio of 100:5, placing two primary con-ductor wraps (two primary turns) through the window will change the ratio to 50:5. Ratio analysis Is a method or process by which the relationship of items or groups of items in the financial statements are computed, and presented. For example, when a learner raises his hand in class, the teacher calls on him every third time he raises his hand. There are five main types of financial ratios discussed. MPH to determine where the ratio's differ between eachother. 3:4= (3\times50,000): (4\times50,000)=150,000:200,000. This involves the side-by-sid. It takes 3 salesmen 8 days to sell 5, 000 boxes of soap. A planetary gearbox works relatively the same. However, they can also be shown in a number of other ways; the three examples below are all different expressions of the same ratio. Plunger pushes up car directly at a 1:1 ratio of plunger-to-car movement. Nine will have at least one gene for both dominate. There are three basic types of curl, mechanical curl, structural curl and moisture curl. Its final drive ratio is 3. Examples of Rate. Mix with care -- a chainsaw is fueled with too much gas in the mixture, it can overheat or malfunction. 0% [58–86 mmol. For example, the average person's trapezius muscle has a fiber ratio of 53. The simplified or reduced ratio " 3 to 4 " tells us only that, for every. It is used to measure how efficient and effective are credit policies of a company. The types are: 1. There are several advertisers. A proof of the Ratio Test is also given. Manufactured by Porsche (ZF) Plate-type limited-slip differential available. The combined fuel consumption of this automobile is 8. 88 (8:31) 915/43. From LearnZillion. Probably the most common scale type is the ratio-scale. However, conversion efficiency falls very rapidly when the engine is operated outside of that band of air-fuel ratios. It may be expressed as a percentage and it reveals the amount of sales required to cover the cost of goods sold plus operating expenses. After checking assignments for a week, you graded all the students. Are these two ratios equivalent? Since the numerators are related (by multiplying or dividing by 3) to each other and the denominators are related to each other, we know these two ratios are equivalent. Similarly, the ratio of lemons to oranges is 6∶8 (or 3∶4) and the ratio of oranges to the total amount of fruit is 8∶14 (or 4∶7). It is very significant to various users of accounting information. 4 Comparing and Graphing Ratios 211 3 ACTIVITY: Comparing Graphs from Ratio Tables Use what you learned about comparing ratios to complete Exercises 3 and 4 on page 214. Solve ratios for the one missing value when comparing ratios or proportions. This site is designed for market research students and professionals. The digit ratio 2D:4D refers to the difference in length between the second digit (index) and fourth digit (ring) fingers. Also works for following question. In order to obtain a ratio of boys to girls equal to 3:5, the number of boys has to be written as 3 x and the number of girls as 5 x where x is a common factor to the number of girls and the number of boys. The quick ratio (sometimes called the acid-test) is similar to the current ratio. Control Ratios. So if you divide 6 and 9 both by 3. It is an irrational number like pi and e, meaning that. There are three basic types of curl, mechanical curl, structural curl and moisture curl. It is an extension of the interval variable and is also the peak of the measurement variable types. To create an exact aspect ratio, divide the height by the width. Other examples of ratio variables include height, mass, distance and many more. 1 inches long and your ring finger is 2. subset_numrows. Understand the concept of a unit rate a/b associated with a ratio a:b with b unequal to 0, and use rate language in the context of a ratio relationship. Year-to-year comparisons can highlight trends and point up the need for action. There are three basic types of pulleys, one that changes the direction of the force, one that changes the. We outline here the basic characteristics of the numeric type class structure and refer the reader to §6. Some types of equipment employ this method to calibrate the equipment or to permit a single ratio CT to be utilized for several different ampacities of equipment. These type of accounting ratios are known as solvency ratios. A new 1:3 CL-20 (2,4,6,8,10,12-hexanitrohexaazaisowurtzitane)/4,5-MDNI (1-methyl-4,5-dinitroimidazole) cocrystal (1) in combination with the previously reported 1:1 CL-20/4,5-MDNI cocrystal (2) together have been first realized in different stoichiometric ratios based on CL-20 and 4,5-MDNI in energetic–energetic cocrystals. Types of Ratios 1. It requires just 10 financial ratios & indicators computed from 17 basic financial inputs. There are four main types of financial statements, which are as follow. One ratio by itself may not give the full picture unless viewed as part of a whole. Lead alloy solder is often referenced by its alloy ratio, such as 60/40 or 63/37, with the first number being the tin by weight and the second number being the amount of lead by weight. The ratio variable is one of the 2 types of continuous variables, where the interval variable is the 2nd. So just like we can reduce fractions, we can also reduce ratios. In fact, artists and sculptors have known about the golden ratio for a long time and have used it to create sculptures and artwork of the ideal. When dominant allele ‘A’ masks the expression of ‘B’ ‘A’ is epistatic gene of ‘B’. Modified Aspect Ratio is a home cinema term for the aspect ratio or dimensions in which a film was modified to fit a specific type of screen, as opposed to original aspect ratio. Examples of the Golden Ratio can be seen everywhere. CRISS-CROSS GRID: a criss-cross grid has two. 5 pounds of corn. For the purpose of promoting health, safety, morals, or the general welfare of the community, the legislative body of every municipality is hereby empowered to regulate and restrict the height, number of stories, and size of buildings and other structures, the percentage of lot that may be occupied, the size of yards, courts, and. An adaptation in nature is acquired through evolution and conveys some type of advantage that help a species to pass its genetic material along to another generation. Some common unit rates are miles (or kilometers) per hour, cost per item, earnings per week, etc. Ratios are expressed as input:output. The decibel scale is a reflection of the logarithmic response of the human ear to changes in sound intensity:. It signifies a company's ability to meet its short-term liabilities with its short-term assets. X2-Test (Chi-Square Test). Observations of this type are on a scale that has a meaningful zero value but also have an equidistant measure (i. An aspect ratio used by 35mm crop sensor and full-frame SLRs, some Leica medium format cameras, mirrorless cameras, high end compacts and most 35mm film cameras. Unlike liquidity that deals with an ability to handle short-term debt, solvency deals with a company’s ability to service its long-term liabilities. This trial investigated the contribution of the liraglutide component of IDegLira versus IDeg alone on efficacy and safety in patients with type 2 diabetes. Method 3: Cross-products. A low debt ratio. A more accepted metric is your debt-to-income ratio. Common liquidity ratios are the current ratio, the quick ratio, and the cash ratio. The most common example of this type of valuation methodology is P/E ratio, which stands for Price to Earnings Ratio. Type 3 Analysis. On most maps, the Representative Fraction is given as. This ratio may be written as 6x:2x:3x where x is a variable. Coverage Ratios 3. Daiwa LEXA-WN400H Lexa Type WN Casting Reel, 400, 6. Three of the four types of productivity are typically important in a software development or IT departments. A pulley consists of a rope and a hub or "drum" in which there is a grooved wheel mounted with an axle. The ratio scales are very common in physical scenarios. Ratio is the spoken language of arithmetic. Blatberwiek University of Minnesota September 1953 g Materials Laboratory Contract No. Examples of Ratio. Financial ratios can be classified into ratios that measure: (1) profitability, (2) liquidity, (3) management efficiency, (4) leverage, and (5) valuation & growth. The table below lists most of the gearbox types, alaong with all their ratios. Two types of Ratio comparisons. • RiskCalc's predictive power derives, in part, from its meticulous transformation of input financial ratios, which are highly 'nonnormally' distributed, as well as the large number of defaulting private firms used in its estimation. 1008364 :: Gearmotors, Type Parallel Shaft, Type of Gears Helical, Ratio 60:1, Output Type Output Shaft (Single), Output Diameter 1/2", Output Torque 100 in-lbs, Output Rpm 28. The current ratio is calculated by simply dividing current assets by current liabilities. No inspections are conducted and there are no standards to meet. 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# Why is the electric charge of a body quantised?

Oct 3, 2014

When scientists say that some sort of property is quantized (charge, energy, etc.), they mean that the property can only have discrete values. Discrete is the opposite of continuous, and it is important to have an example for both to highlight the distinction.

To think of a continuous property, consider driving from home to school, and suppose your school is exactly one kilometre away. On your drive, you could be anywhere between your house and the school. You could be half a kilometre away (0.5 km), one third of a kilometre away (0.33 km), or an even more precise distance such as 0.4773822 km way. Since you could hypothetically be anywhere along the entire 1 km spectrum, distance can be thought of as a continuous property.

For a discrete property, consider climbing up a flight of stairs. If there are a total of 10 stairs, it is possible to be on stair 1, or 2, or 3, and so on. But it's not possible to be on stair number two and a half, stair number 6.8743. In other words, the possible value for stair numbers is discrete, or quantized.

Now we will look at this distinction in the context of electric charge. At the most elementary level, charge is controlled by the combined total number of protons and electrons. If an object has an excess of electrons relative to protons, it will be negatively charged. The question becomes, "how much negative charge"?

Charge is measured in units of Coulombs, C. Each proton has a charge of $+ 1.602 \cdot {10}^{-} 19 C$ and each electron has a charge of $- 1.602 \cdot {10}^{-} 19 C$, which we can denote as $+ e$ or $- e$. Just to be clear,

$e = 1.602 \cdot {10}^{-} 19 C$

So any object, or body, with a net charge (i.e. excess of either protons or electrons) must have a value of plus or minus $e$, or $2 e$, or $3 e$, and so on (in technical terms, an integer multiple of $e$). However, it would be impossible for an object to have a charge of $+ 1.3 e$ or $- 4.57 e$.

For further information, take a look at the following resource: http://en.wikipedia.org/wiki/Elementary_charge#Quantization.

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nLab commutativity of limits and colimits

Context

Limits and colimits

limits and colimits

Contents

Idea

In general, limits and colimits do not commute.

It is therefore of interest to list the special conditions under which certain limits do commute with certain colimits.

This page lists some of these.

Filtered colimits commute with finite limits

For $C$ a small filtered category, the functor ${\mathrm{colim}}_{C}:\left[C,\mathrm{Set}\right]\to \mathrm{Set}$ commutes with finite limits.

More in detail, let

• $C$ be a small filtered category

• $D$ be a finite category;

• $F:C×{D}^{\mathrm{op}}\to \mathrm{Set}$ a functor;

then the canonical morphism

${\mathrm{colim}}_{C}{\mathrm{lim}}_{D}F\stackrel{\simeq }{\to }{\mathrm{lim}}_{D}{\mathrm{colim}}_{C}F$colim_C lim_D F \stackrel{\simeq}{\to} lim_D colim_C F

is an isomorphism.

In fact, $C$ is a filtered category if and only if this is true for all finite $D$ and all functors $F:C×{D}^{\mathrm{op}}\to \mathrm{Set}$.

Sifted colimits commute with finite products

Similarly to the example of filtered limits, for $C$ a small sifted category, the functor ${\mathrm{colim}}_{C}:\left[C,\mathrm{Set}\right]\to \mathrm{Set}$ commutes with finite products. In fact, this is usually taken to be the definition of a sifted category, and then a theorem of Gabriel and Ulmer characterizes sifted categories as those for which the diagonal functor $C\to C×C$ is a final functor.

Taking orbits under the action of a finite group commutes with cofiltered limits

More precisely, if $G$ is a finite group, $C$ is a small cofiltered category and $F:C\to G-\mathrm{Set}$ is a functor, the canonical map

$\left(\mathrm{lim}F\right)/G\to \underset{j\in F}{\mathrm{lim}}\left(F\left(j\right)/G\right)$(\lim F)/G \to \lim_{j \in F} (F(j)/G)

is an isomorphism. This fact is mentioned by André Joyal in Foncteurs analytiques et espèces de structures; a proof can be found here.

Certain colimits are stable by base change

Let $C$ be a category with pullbacks and colimits of shape $D$.

We say that colimits of shape $D$ are stable by base change or stable under pullback if for every functor $F:D\to C$ and for all pullback diagrams of the form

$\begin{array}{ccc}\left({\mathrm{colim}}_{D}F\right){×}_{Z}Y& \to & {\mathrm{colim}}_{D}F\\ ↓& & ↓\\ Y& \to & Z\end{array}$\array{ (colim_D F) \times_Z Y &\to& colim_D F \\ \downarrow && \downarrow \\ Y &\to & Z }

the canonical morphism

${\mathrm{colim}}_{d\in D}\left(F\left(d\right){×}_{Z}Y\right)\stackrel{\simeq }{\to }\left({\mathrm{colim}}_{D}F\right){×}_{Z}Y$colim_{d \in D} (F(d) \times_Z Y) \stackrel{\simeq}{\to} (colim_D F) \times_Z Y

is an isomorphism.

All colimits are stable under base change in for instance

• $C=$ Set;
• hence for $C=$ a presheaf category $\left[{S}^{\mathrm{op}},\mathrm{Set}\right]$ (since colimits in such $C$ are computed objectwise in $\mathrm{Set}$), see limits and colimits by example);
• more generally, any topos;

but not in for instance

• $C=$ Ab.

Remark

In topos theory and (∞,1)-topos theory one says that colimits are universal if they are preserved under pullback.

Revised on August 14, 2013 18:18:01 by Anonymous Coward (38.96.165.241)


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## Introduction

This is the post of 2020, so新年快乐给你所有！

I’m a huge fan of LLVM since 11 years ago when I started playing with it toJIT data structures如AVLS，然后稍后JIT限制AST树JIT native code from TensorFlow graphs。此后，LLVM演变成最重要的编译器框架的生态系统之一，是由很多重要的开源项目采用了时下。

The image below gives an overview of Gandiva:

## 建设有Gandiva简单的表达

### Using Gandiva Python bindings to JIT and expression

Before building our parser and expression builder for expressions, let’s manually build a simple expression with Gandiva. First, we will create a simple Pandas DataFrame with numbers from 0.0 to 9.0:

import pandas as pd import pyarrow as pa import pyarrow.gandiva as gandiva # Create a simple Pandas DataFrame df = pd.DataFrame({"x": [1.0 * i for i in range(10)]}) table = pa.Table.from_pandas(df) schema = pa.Schema.from_pandas(df)

（X> 2.0）和（x <6.0）

助洗剂= gandiva.TreeExprBuilder（）＃参考列的 “x” node_x = builder.make_field（table.schema.field（ “×”））＃提出两个文字：2.0和6.0 2 = builder.make_literal（2.0，pa.float64（））6 = builder.make_literal（6.0，pa.float64（））＃为 “X> 2.0” gt_five_node = builder.make_function一个函数（ “GREATER_THAN”，[node_x，两]，pa.bool_（））＃创建 “×<6.0” 的函数lt_ten_node = builder.make_function（ “LESS_THAN”，[node_x，六]，pa.bool_（））＃创建一个 “和” 节点，为“（X> 2.0）和（x <6.0）” and_node = builder.make_and（[gt_five_node，lt_ten_node]）＃使表达的条件，并创建一个过滤条件= builder.make_condition（and_node）filter_ = gandiva.make_filter（table.schema，条件）

This code now looks a little more complex but it is easy to understand. We are basically creating the nodes of a tree that will represent the expression we showed earlier. Here is a graphical representation of what it looks like:

### Inspecting the generated LLVM IR

auto field_x = field("x", float32()); auto schema = arrow::schema({field_x}); auto node_x = TreeExprBuilder::MakeField(field_x); auto two = TreeExprBuilder::MakeLiteral((float_t)2.0); auto six = TreeExprBuilder::MakeLiteral((float_t)6.0); auto gt_five_node = TreeExprBuilder::MakeFunction("greater_than", {node_x, two}, arrow::boolean()); auto lt_ten_node = TreeExprBuilder::MakeFunction("less_than", {node_x, six}, arrow::boolean()); auto and_node = TreeExprBuilder::MakeAnd({gt_five_node, lt_ten_node}); auto condition = TreeExprBuilder::MakeCondition(and_node); std::shared_ptr filter; auto status = Filter::Make(schema, condition, TestConfiguration(), &filter);

The code above is the same as the Python code, but using the C++ Gandiva API. Now that we built the tree in C++, we can get the LLVM Module and dump the IR code for it. The generated IR is full of boilerplate code and the JIT’ed functions from the Gandiva registry, however the important parts are show below:

; Function Attrs: alwaysinline norecurse nounwind readnone ssp uwtable define internal zeroext i1 @less_than_float32_float32(float, float) local_unnamed_addr #0 { %3 = fcmp olt float %0, %1 ret i1 %3 } ; Function Attrs: alwaysinline norecurse nounwind readnone ssp uwtable define internal zeroext i1 @greater_than_float32_float32(float, float) local_unnamed_addr #0 { %3 = fcmp ogt float %0, %1 ret i1 %3 } (...) %x = load float, float* %11 %greater_than_float32_float32 = call i1 @greater_than_float32_float32(float %x, float 2.000000e+00) (...) %x11 = load float, float* %15 %less_than_float32_float32 = call i1 @less_than_float32_float32(float %x11, float 6.000000e+00)

As you can see, on the IR we can see the call to the functionsless_than_float32_float_32andgreater_than_float32_float32这是（在这种情况下很简单的）Gandiva功能做浮动比亚洲金博宝较。通过查看函数名前缀注意函数的专业化。

%x.us = load float, float* %10, align 4 %11 = fcmp ogt float %x.us, 2.000000e+00 %12 = fcmp olt float %x.us, 6.000000e+00 %not.or.cond = and i1 %12, %11

## 建设有Gandiva一个熊猫过滤器表达式JIT

Now we want to be able to implement something similar as the Pandas’DataFrame.query()function using Gandiva. The first problem we will face is that we need to parse a string such as（X> 2.0）和（x <6.0），以后我们将不得不建立使用从Gandiva树构建的Gandiva表达式树，然后评估上箭头的数据表达。

Now, instead of implementing a full parsing of the expression string, I’ll use the Python AST module to parse valid Python code and build an Abstract Syntax Tree (AST) of that expression, that I’ll be later using to emit the Gandiva/LLVM nodes.

class LLVMGandivaVisitor(ast.NodeVisitor): def __init__(self, df_table): self.table = df_table self.builder = gandiva.TreeExprBuilder() self.columns = {f.name: self.builder.make_field(f) for f in self.table.schema} self.compare_ops = { "Gt": "greater_than", "Lt": "less_than", } self.bin_ops = { "BitAnd": self.builder.make_and, "BitOr": self.builder.make_or, } def visit_Module(self, node): return self.visit(node.body[0]) def visit_BinOp(self, node): left = self.visit(node.left) right = self.visit(node.right) op_name = node.op.__class__.__name__ gandiva_bin_op = self.bin_ops[op_name] return gandiva_bin_op([left, right]) def visit_Compare(self, node): op = node.ops[0] op_name = op.__class__.__name__ gandiva_comp_op = self.compare_ops[op_name] comparators = self.visit(node.comparators[0]) left = self.visit(node.left) return self.builder.make_function(gandiva_comp_op, [left, comparators], pa.bool_()) def visit_Num(self, node): return self.builder.make_literal(node.n, pa.float64()) def visit_Expr(self, node): return self.visit(node.value) def visit_Name(self, node): return self.columns[node.id] def generic_visit(self, node): return node def evaluate_filter(self, llvm_mod): condition = self.builder.make_condition(llvm_mod) filter_ = gandiva.make_filter(self.table.schema, condition) result = filter_.evaluate(self.table.to_batches()[0], pa.default_memory_pool()) arr = result.to_array() pd_result = arr.to_numpy() return pd_result @staticmethod def gandiva_query(df, query): df_table = pa.Table.from_pandas(df) llvm_gandiva_visitor = LLVMGandivaVisitor(df_table) mod_f = ast.parse(query) llvm_mod = llvm_gandiva_visitor.visit(mod_f) results = llvm_gandiva_visitor.evaluate_filter(llvm_mod) return results

### 注册为熊猫扩展

@ pd.api.extensions.register_dataframe_accessor（ “gandiva”）类GandivaAcessor：高清__init __（自我，pandas_obj）：self.pandas_obj = pandas_obj高清查询（个体经营，查询）：返回LLVMGandivaVisitor.gandiva_query（self.pandas_obj，查询）

df = pd.DataFrame({"a": [1.0 * i for i in range(nsize)]}) results = df.gandiva.query("a > 10.0")

As we have registered a Pandas extension calledgandiva这是现在的大熊猫DataFrames的一等公民。

df = pd.DataFrame({"a": [1.0 * i for i in range(50000000)]}) df.gandiva.query("a < 4.0") # This will output: # array([0, 1, 2, 3], dtype=uint32)

That’s it ! I hope you liked the post as I enjoyed exploring Gandiva. It seems that we will probably have more and more tools coming up with Gandiva acceleration, specially for SQL parsing/projection/JITing. Gandiva is much more than what I just showed, but you can get started now to understand more of its architecture and how to build the expression trees.

– Christian S. Perone

## Listening to the neural network gradient norms during training

Training neural networks is often done by measuring many different metrics such as accuracy, loss, gradients, etc. This is most of the time done aggregating these metrics and plotting visualizations on TensorBoard.

There are, however, other senses that we can use to monitor the training of neural networks, such as声音。Sound is one of the perspectives that is currently very poorly explored in the training of neural networks. Human hearing can be very good a distinguishing very small perturbations in characteristics such as rhythm and pitch, even when these perturbations are very short in time or subtle.

### Training sound with Adam using LR 0.01

This is using Adam in the same setting as the SGD.

## Source code

For those who are interested, here is the entire source code I used to make the sound clips:

进口pyaudio进口numpy np波不进口rt torch import torch.nn as nn import torch.nn.functional as F import torch.optim as optim from torchvision import datasets, transforms class Net(nn.Module): def __init__(self): super(Net, self).__init__() self.conv1 = nn.Conv2d(1, 20, 5, 1) self.conv2 = nn.Conv2d(20, 50, 5, 1) self.fc1 = nn.Linear(4*4*50, 500) self.fc2 = nn.Linear(500, 10) self.ordered_layers = [self.conv1, self.conv2, self.fc1, self.fc2] def forward(self, x): x = F.relu(self.conv1(x)) x = F.max_pool2d(x, 2, 2) x = F.relu(self.conv2(x)) x = F.max_pool2d(x, 2, 2) x = x.view(-1, 4*4*50) x = F.relu(self.fc1(x)) x = self.fc2(x) return F.log_softmax(x, dim=1) def open_stream(fs): p = pyaudio.PyAudio() stream = p.open(format=pyaudio.paFloat32, channels=1, rate=fs, output=True) return p, stream def generate_tone(fs, freq, duration): npsin = np.sin(2 * np.pi * np.arange(fs*duration) * freq / fs) samples = npsin.astype(np.float32) return 0.1 * samples def train(model, device, train_loader, optimizer, epoch): model.train() fs = 44100 duration = 0.01 f = 200.0 p, stream = open_stream(fs) frames = [] for batch_idx, (data, target) in enumerate(train_loader): data, target = data.to(device), target.to(device) optimizer.zero_grad() output = model(data) loss = F.nll_loss(output, target) loss.backward() norms = [] for layer in model.ordered_layers: norm_grad = layer.weight.grad.norm() norms.append(norm_grad) tone = f + ((norm_grad.numpy()) * 100.0) tone = tone.astype(np.float32) samples = generate_tone(fs, tone, duration) frames.append(samples) silence = np.zeros(samples.shape[0] * 2, dtype=np.float32) frames.append(silence) optimizer.step() # Just 200 steps per epoach if batch_idx == 200: break wf = wave.open("sgd_lr_1_0_bs256.wav", 'wb') wf.setnchannels(1) wf.setsampwidth(p.get_sample_size(pyaudio.paFloat32)) wf.setframerate(fs) wf.writeframes(b''.join(frames)) wf.close() stream.stop_stream() stream.close() p.terminate() def run_main(): device = torch.device("cpu") train_loader = torch.utils.data.DataLoader( datasets.MNIST('../data', train=True, download=True, transform=transforms.Compose([ transforms.ToTensor(), transforms.Normalize((0.1307,), (0.3081,)) ])), batch_size=256, shuffle=True) model = Net().to(device) optimizer = optim.SGD(model.parameters(), lr=0.01, momentum=0.5) for epoch in range(1, 2): train(model, device, train_loader, optimizer, epoch) if __name__ == "__main__": run_main()
Cite this article as: Christian S. Perone, "Listening to the neural network gradient norms during training," inTerra Incognita, 04/08/2019,//www.cpetem.com/2019/08/listening-to-the-neural-network-gradient-norms-during-training/

## Randomized prior functions in PyTorch

The main idea of the method is to have bootstrap to provide a non-parametric data perturbation together with randomized priors, which are nothing more than just random initialized networks.

$$Q _ {\ theta_k}（X）= F _ {\ theta_k}（X）+ P_K（x）的$$

The final model $$Q_{\theta_k}(x)$$ will be the k model of the ensemble that will fit the function $$f_{\theta_k}(x)$$ with an untrained prior $$p_k(x)$$.

Let’s go to the code. The first class is a simple MLP with 2 hidden layers and Glorot initialization :

类MLP（nn.Module）：DEF __init __（个体）：超级（）.__ INIT __（）self.l1 = nn.Linear（1，20）self.l2 = nn.Linear（20，20）self.l3 = NN。Linear(20, 1) nn.init.xavier_uniform_(self.l1.weight) nn.init.xavier_uniform_(self.l2.weight) nn.init.xavier_uniform_(self.l3.weight) def forward(self, inputs): x = self.l1(inputs) x = nn.functional.selu(x) x = self.l2(x) x = nn.functional.selu(x) x = self.l3(x) return x

Then later we define a class that will take the model and the prior to produce the final model result:

class ModelWithPrior(nn.Module): def __init__(self, base_model : nn.Module, prior_model : nn.Module, prior_scale : float = 1.0): super().__init__() self.base_model = base_model self.prior_model = prior_model self.prior_scale = prior_scale def forward(self, inputs): with torch.no_grad(): prior_out = self.prior_model(inputs) prior_out = prior_out.detach() model_out = self.base_model(inputs) return model_out + (self.prior_scale * prior_out)

And it’s basically that ! As you can see, it’s a very simple method, in the second part we just created a custom forward() to avoid computing/accumulating gradients for the prior network and them summing (after scaling) it with the model prediction.

DEF train_model（x_train，y_train，base_model，prior_model）：模型= ModelWithPrior（base_model，prior_model，1.0）loss_fn = nn.MSELoss（）优化= torch.optim.Adam（model.parameters（），LR = 0.05）为在历元范围（100）：model.train（）preds =模型（x_train）损耗= loss_fn（preds，y_train）optimizer.zero_grad（）loss.backward（）optimizer.step（）的返回模型

and using a sampler with replacement (bootstrap) as in:

数据集= TensorDataset（...）bootstrap_sampler = RandomSampler（数据集，TRUE，LEN（数据集））train_dataloader =的DataLoader（数据集，=的batch_size LEN（数据集），采样= bootstrap_sampler）

In this case, I used the same small dataset used in the original paper:

If we look at just the priors, we will see the variation of the untrained networks:

We can also visualize the individual model predictions showing their variability due to different initializations as well as the bootstrap noise:

Now, what is also quite interesting, is that we can change the prior to let’s say a fixed sine:

类SinPrior（nn.Module）：高清向前（个体经营，输入）：返回torch.sin（3 *输入）

Then, when we train the same MLP model but this time using the sine prior, we can see how it affects the final prediction and uncertainty bounds:

If we show each individual model, we can see the effect of the prior contribution to each individual model:

Cite this article as: Christian S. Perone, "Randomized prior functions in PyTorch," inTerra Incognita, 24/03/2019,//www.cpetem.com/2019/03/randomized-prior-functions-in-pytorch/

## 188bet开户平台

*这篇文章是在葡萄牙语。It’s a bayesian analysis of a Brazilian national exam. The main focus of the analysis is to understand the underlying factors impacting the participants performance on ENEM.

Este tutorial apresenta uma análise breve dos microdados do ENEM do Rio Grande do Sul do ano de 2017. O principal objetivo é entender os fatores que impactam na performance dos participantes do ENEM dado fatores como renda familiar e tipo de escola. Neste tutorial são apresentados dois modelos: regressão linear e regressão linear hierárquica.

188bet开户平台

## 188betiosapp

Update 28 Feb 2019:我添加了一个new blog post with a slide deck包括我做了PyData蒙特利尔的表现。

Today, at the PyTorch Developer Conference, the PyTorch team announced the plans and the release of the PyTorch 1.0 preview with many nice features such as a JIT for model graphs (with and without tracing) as well as theLibTorch中，PyTorch C ++ API中的所述一个most important release announcementmade today in my opinion.

### Introduction

Simply put, the libtorch is a library version of the PyTorch. It contains the underlying foundation that is used by PyTorch, such as theATen（张量库），它包含了所有的张量操作和方法。还Libtorch包含autograd, which is the component that adds the automatic differentiation to the ATen tensors.

A word of caution for those who are starting now is to be careful with the use of the tensors that can be created both from ATen and autograd,不要混合使用它们, the ATen will return the plain tensors (when you create them using theatnamespace) while the autograd functions (from the火炬命名空间）将返回Variable中，加入其自动分化机制。

Libtorch可以从下载Pytorch网站它仅作为一会儿预览。您还可以找到文档this site，这主要是一个Doxygen的渲染文档。我发现图书馆相当稳定，这是有道理的，因为它实际上是暴露PyTorch的稳定基础，但是，也有一些问题，标题和一些小问题，关于图书馆的组织，而开始使用它，你可能会发现（将希望尽快修复）。

For NodeJS, I’ll use the本土抽象库（楠），这是最值得推荐的库（实际上基本是仅标头库）来创建的NodeJS C ++的附加组件和cmake的-JS, because libtorch already provide the cmake files that make our building process much easier. However, the focus here will be on the C++ code and not on the building process.

The flow for the development, tracing, serializing and loading the model can be seen in the figure on the left side.

It starts with the development process and tracing being done in PyTorch (Python domain) and then the loading and inference on the C++ domain (in our case in NodeJS add-on).

### 结束语张量

的#ifndef TENSOR_H的#define TENSOR_H的#include 的#include <炬/ torch.h>命名空间torchjs {类张量：公共楠:: ObjectWrap {公共：静态NAN_MODULE_INIT（初始化）;空隙setTensor（在::张量张量）{这个 - > mTensor =张量;}炬::张量getTensor（）{返回这个 - > mTensor;}静态V8 ::本地 NewInstance方法（）;私人：明确的张量（）;张量〜（）;静态NAN_METHOD（新）;静态NAN_METHOD（的toString）;静态楠::持久构造;私人：火炬::张量mTensor; }; } // namespace torchjs #endif

I won’t show all the implementation details because most parts of it are NodeJS boilerplate code to construct the object, etc. I’ll focus on the parts that touch the libtorch API, like in the code below where we are creating a small textual representation of the tensor to show on JavaScript (toStringmethod):

NAN_METHOD(Tensor::toString) { Tensor* obj = ObjectWrap::Unwrap(info.Holder()); std::stringstream ss; at::IntList sizes = obj->mTensor.sizes(); ss << "Tensor[Type=" << obj->mTensor.type() << ", "; ss << "Size=" << sizes << std::endl; info.GetReturnValue().Set(Nan::New(ss.str()).ToLocalChecked()); }

### 包装张量创建操作

NAN_METHOD（个）{//理智的参数检查，如果（info.Length（）<2）返回楠:: ThrowError（楠::新（ “错误的数目的参数”）ToLocalChecked（））;如果（！信息[0]  - > IsArray的（）||信息[1]  - > IsBoolean（）！）返回楠:: ThrowError（楠::新（ “错误的参数类型”）ToLocalChecked（））;//检索参数（require_grad和张量形状）const的布尔require_grad =信息[1]  - > BooleanValue中（）;常量V8 ::本地阵列=信息[0]。如（）;常量uint32_t的长度=阵列 - >长度（）;//从V8 ::数组转换为标准::矢量的std ::矢量<长长>变暗;对于（中间体I = 0;我<长度;我++）{V8 ::本地 V;INT d =阵列 - >获取（ⅰ） - > NumberValue（）;dims.push_back（d）;} //调用libtorch并创建一个新torchjs ::张量对象//包装新火炬::张量，是由火炬创建::在::张量V =火炬::一（变暗，火炬:: requires_grad的人（require_grad））; auto newinst = Tensor::NewInstance(); Tensor* obj = Nan::ObjectWrap::Unwrap(newinst); obj->setTensor(v); info.GetReturnValue().Set(newinst); }

And that’s it, we just exposed one torch operation that can be used as native JavaScript operation.

### Intermezzo for the PyTorch JIT

The introduced PyTorch JIT revolves around the concept of the Torch Script. A Torch Script is a restricted subset of the Python language and comes with its own compiler and transform passes (optimizations, etc).

Note that if you have branching decisions on your code that depends on external factors or data, tracing won’t work as you expect because it will record that particular execution of the graph, hence the alternative option to provide the script. However, in most of the cases, the tracing is what we need.

To understand the differences, let’s take a look at the Intermediate Representation (IR) from the script module generated both by tracing and by scripting.

@ torch.jit.script DEF happy_function_script（X）：RET = torch.rand（0）如果真== TRUE：RET = torch.rand（1）否则：RET = torch.rand（2）返回RET DEF happy_function_trace（X）：t RET = torch.rand（0）如果真== TRUE：RET = torch.rand（1）否则：RET = torch.rand（2）返回RET traced_fn = torch.jit.trace（happy_function_trace，（torch.tensor（0），），check_trace = FALSE）

# 1) Graph from the scripting approach graph(%x : Dynamic) { %16 : int = prim::Constant[value=2]() %10 : int = prim::Constant[value=1]() %7 : int = prim::Constant[value=1]() %8 : int = prim::Constant[value=1]() %9 : int = aten::eq(%7, %8) %ret : Dynamic = prim::If(%9) block0() { %11 : int[] = prim::ListConstruct(%10) %12 : int = prim::Constant[value=6]() %13 : int = prim::Constant[value=0]() %14 : int[] = prim::Constant[value=[0, -1]]() %ret.2 : Dynamic = aten::rand(%11, %12, %13, %14) -> (%ret.2) } block1() { %17 : int[] = prim::ListConstruct(%16) %18 : int = prim::Constant[value=6]() %19 : int = prim::Constant[value=0]() %20 : int[] = prim::Constant[value=[0, -1]]() %ret.3 : Dynamic = aten::rand(%17, %18, %19, %20) -> (%ret.3) } return (%ret); } # 2) Graph from the tracing approach graph(%0 : Long()) { %7 : int = prim::Constant[value=1]() %8 : int[] = prim::ListConstruct(%7) %9 : int = prim::Constant[value=6]() %10 : int = prim::Constant[value=0]() %11 : int[] = prim::Constant[value=[0, -1]]() %12 : Float(1) = aten::rand(%8, %9, %10, %11) return (%12); }

PyTorch JIT有很多被用来做循环展开改造通行证，死代码消除等。您可以找到这些的这里传递。不是转换成其它格式，例如ONNX可以被实施为在该中间表示（IR），这是相当方便的顶部一通。

### Tracing the ResNet

Now, before implementing the Script Module in NodeJS, let’s first trace a ResNet network using PyTorch (using just Python):

traced_net = torch.jit.trace（torchvision.models.resnet18（），torch.rand（1，3，224，224））traced_net.save（ “resnet18_trace.pt”）

As you can see from the code above, we just have to provide a tensor example (in this case a batch of a single image with 3 channels and size 224×224. After that we just save the traced network into a file calledresnet18_trace.pt

### 包裹脚本模块

// Class构造ScriptModule :: ScriptModule（常量的std :: string文件名）{//加载从文件这 - > mModule =炬:: JIT ::负载（文件名）所追踪的网络;} // JavaScript对象创建NAN_METHOD（ScriptModule ::新）{如果（info.IsConstructCall（））{//获取文件名参数V8 ::字符串:: Utf8Value param_filename（信息[0]  - >的ToString（））;常量的std :: string文件名=的std :: string（* param_filename）;//使用该文件名ScriptModule * OBJ =新ScriptModule（文件名）创建一个新的脚本模块;obj->裹（info.This（））;。info.GetReturnValue（）设置（info.This（））;}否则{V8 ::本地缺点=楠::新（构造）;。info.GetReturnValue（）设置（楠:: NewInstance方法（缺点）.ToLocalChecked（））;}}

The wrapping of the forward pass is also quite straightforward:

NAN_METHOD（ScriptModule ::向前）{ScriptModule * script_module = ObjectWrap ::展开（info.Holder（））;楠:: MaybeLocal 说不定=楠::要（信息[0]）;张量*张量=楠:: ObjectWrap ::展开<张量>（maybe.ToLocalChecked（））;火炬::张量torch_tensor = tensor-> getTensor（）;火炬::张量输出= script_module-> mModule->向前（{torch_tensor}）toTensor（）;自动newinst中=张量:: NewInstance方法（）;张量* OBJ =楠:: ObjectWrap ::展开<张量>（newinst中）;obj-> setTensor（输出）;。info.GetReturnValue（）设置（newinst中）;}

As you can see, in this code, we just receive a tensor as an argument, we get the internal火炬::Tensorfrom it and then call the forward method from the script module, we wrap the output on a new火炬js::Tensor和n return it.

VAR torchjs =需要（ “./构建/释放/ torchjs”）;VAR = script_module新torchjs.ScriptModule（ “resnet18_trace.pt”）;VAR数据= torchjs.ones（[1，3，224，224]，假）;VAR输出= script_module.forward（数据）;

– Christian S. Perone

## PyTorch – Internal Architecture Tour

Update 28 Feb 2019:我添加了一个new blog post with a slide deck包括我做了PyData蒙特利尔的表现。

## 短介绍到Python扩展在C / C ++对象

As you probably know, you can extend Python using C and C++ and develop what is called as “extension”. All the PyTorch heavy work is implemented in C/C++ instead of pure-Python. To define a new Python object type in C/C++, you define a structure like this one example below (which is the base for the autogradVariable类）：

// Python对象即背torch.autograd.Variable结构THPVariable {PyObject_HEAD炬:: autograd ::可变CDATA;*的PyObject backward_hooks;};

Funny fact：这是在许多应用亚洲金博宝中非常普遍使用小整数作为索引，计数器等为了提高效率，官方CPython interpretercaches the integers from -5 up to 256. For that reason, the statement一个= 200;B = 200;A是B将会True，而声明一个= 300;B = 300;A是B将会

## Zero-copy PyTorch Tensor to Numpy and vice-versa

PyTorch has its own Tensor representation, which decouples PyTorch internal representation from external representations. However, as it is very common, especially when data is loaded from a variety of sources, to have Numpy arrays everywhere, therefore we really need to make conversions between Numpy and PyTorch tensors. For that reason, PyTorch provides two methods calledfrom_numpy（）andnumpy()，其将一个numpy的阵列，反之亦然，分别PyTorch阵列和。如果我们看就是被称为一个numpy的数组转换成PyTorch张量的代码，我们可以得到在PyTorch的内部表示更多的见解：

at::Tensor tensor_from_numpy(PyObject* obj) { if (!PyArray_Check(obj)) { throw TypeError("expected np.ndarray (got %s)", Py_TYPE(obj)->tp_name); } auto array = (PyArrayObject*)obj; int ndim = PyArray_NDIM(array); auto sizes = to_aten_shape(ndim, PyArray_DIMS(array)); auto strides = to_aten_shape(ndim, PyArray_STRIDES(array)); // NumPy strides use bytes. Torch strides use element counts. auto element_size_in_bytes = PyArray_ITEMSIZE(array); for (auto& stride : strides) { stride /= element_size_in_bytes; } // (...) - omitted for brevity void* data_ptr = PyArray_DATA(array); auto& type = CPU(dtype_to_aten(PyArray_TYPE(array))); Py_INCREF(obj); return type.tensorFromBlob(data_ptr, sizes, strides, [obj](void* data) { AutoGIL gil; Py_DECREF(obj); }); }

（代码从tensor_numpy.cpp)

After this, PyTorch will create a new Tensor object from this Numpy data blob, and in the creation of this new Tensor it passes the borrowed memory data pointer, together with the memory size and strides as well as a function that will be used later by the Tensor Storage (we’ll discuss this in the next section) to release the data by decrementing the reference counting to the Numpy array object and let Python take care of this object life cycle.

ThetensorFromBlob（）方法将创建一个新的张量，但只有创建一个新的“存储”这个张量之后。存储是其中实际数据指针将被存储（而不是在张量结构本身）。这需要我们去了解下部分张量储量

## 张量存储

The actual raw data of the Tensor is not directly kept in the Tensor structure, but on another structure called Storage, which in turn is part of the Tensor structure.

As we saw in the previous code fromtensor_from_numpy（）, there is a call fortensorFromBlob（）that will create a Tensor from the raw data blob. This last function will call another function called storageFromBlob() that will, in turn, create a storage for this data according to its type. In the case of a CPU float type, it will return a newCPUFloatStorage实例。

typedef struct THStorage { real *data; ptrdiff_t size; int refcount; char flag; THAllocator *allocator; void *allocatorContext; struct THStorage *view; } THStorage;

（代码从THStorage.h)

>>> tensor_a = torch.ones((3, 3)) >>> tensor_b = tensor_a.view(9) >>> tensor_a.storage().data_ptr() == tensor_b.storage().data_ptr() True

As we can see in the example above, the data pointer on the storage of both Tensors are the same, but the Tensors represent a different interpretation of the storage data.

typedef结构THAllocator {无效*（* malloc的）（无效*，ptrdiff_t的）;无效*（* realloc的）（无效*，无效*，ptrdiff_t的）;空隙（*免费）（无效*，无效*）;} THAllocator;

（代码从THAllocator.h)

static void *THCudaHostAllocator_malloc(void* ctx, ptrdiff_t size) { void* ptr; if (size < 0) THError("Invalid memory size: %ld", size); if (size == 0) return NULL; THCudaCheck(cudaMallocHost(&ptr, size)); return ptr; }

（代码从THCAllocator.c)

You probably noticed a pattern in the repository organization, but it is important to keep in mind these conventions when navigating the repository, as summarized here (taken from thePyTorch LIB自述）：

• TH=TorcH
• THC=TorcHCuda
• THCS=TorcHCudaS解析
• THCUNN=TorcHCUdaNeuralNetwork
• THD=TorcHDistributed
• THNN=TorcHNeuralNetwork
• THS=TorcH 2 S解析

Finally, we can see the composition of the main TensorTHTensor结构体：

typedef结构THTensor {*的int64_t大小;*的int64_t步幅;INT n标注;THStorage *存储;ptrdiff_t的storageOffset;INT引用计数;焦标志;} THTensor;

（从代码THTensor.h)

We can summarize all this structure that we saw in the diagram below:

## Shared Memory

PyTorch provides a wrapper around the Python多模块，并且可以从被导入火炬。多。他们在各地官方Python多这个包装实施的变化做是为了确保每次张量放在一个队列或共享与另一个进程，PyTorch将确保只对共享内存的句柄将被共享，而不是亚洲金博宝张量的新的完整副本。

static THStorage* THPStorage_(newFilenameStorage)(ptrdiff_t size) { int flags = TH_ALLOCATOR_MAPPED_SHAREDMEM | TH_ALLOCATOR_MAPPED_EXCLUSIVE; std::string handle = THPStorage_(__newHandle)(); auto ctx = libshm_context_new(NULL, handle.c_str(), flags); return THStorage_(newWithAllocator)(size, &THManagedSharedAllocator, (void*)ctx); }

（从代码StorageSharing.cpp)

Note: when a method ends with a underscore in PyTorch, such as the method calledshare_memory_()，这意味着，该方法具有就地效果，它将改变当前对象，而不是创建一个新的与改进的。

I’ll now show a Python example of one processing using the data from a Tensor that was allocated on another process by manually exchanging the shared memory handle:

This is executed in the process A:

>>>进口炬>>> tensor_a = torch.ones（（5,5））>>> tensor_a 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 [火炬。FloatTensor of size 5x5] >>> tensor_a.is_shared() False >>> tensor_a = tensor_a.share_memory_() >>> tensor_a.is_shared() True >>> tensor_a_storage = tensor_a.storage() >>> tensor_a_storage._share_filename_() (b'/var/tmp/tmp.0.yowqlr', b'/torch_31258_1218748506', 25)

Code executed in the process B:

>>>进口炬>>> tensor_a = torch.Tensor（）>>> tuple_info =（B '/ var / tmp中/ tmp.0.yowqlr'，B '/ torch_31258_1218748506'，25）>>>存储=炬。Storage._new_shared_filename（* tuple_info）>>> tensor_a = torch.Tensor（存储）。查看（（5,5））1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 11 1 [5×5大小的torch.FloatTensor]

## DLPack: a hope for the Deep Learning frameworks Babel

Now I would like to talk about something recent in the PyTorch code base, that is calledDLPack。DLPack是一个内存张量结构，其将允许交换张量数据的一个开放的标准化框架之间, and what is quite interesting is that since this memory representation is standardized and very similar to the memory representation already in use by many frameworks, it will allow azero-copy data sharing between frameworks, which is a quite amazing initiative given the variety of frameworks we have today without inter-communication among them.

DLPack的核心操作系统被称为结构非常简单亚洲金博宝DLTensor， 如下所示：

/ * !* \短暂纯C张量对象,并不等内容e memory. */ typedef struct { /*! * \brief The opaque data pointer points to the allocated data. * This will be CUDA device pointer or cl_mem handle in OpenCL. * This pointer is always aligns to 256 bytes as in CUDA. */ void* data; /*! \brief The device context of the tensor */ DLContext ctx; /*! \brief Number of dimensions */ int ndim; /*! \brief The data type of the pointer*/ DLDataType dtype; /*! \brief The shape of the tensor */ int64_t* shape; /*! * \brief strides of the tensor, * can be NULL, indicating tensor is compact. */ int64_t* strides; /*! \brief The offset in bytes to the beginning pointer to data */ uint64_t byte_offset; } DLTensor;

（代码从dlpack.h)

There is also a managed version of the tensor that is calledDLManagedTensor，其中框架可以提供一个框架，并且可以通过谁借了张量来通知资源不再需要其他的框架，框架调用也是一个“删除器”的功能。

In PyTorch, if you want to convert to or from a DLTensor format, you can find both C/C++ methods for doing that or even in Python you can do that as shown below:

从进口torch.utils炬导入dlpack吨= torch.ones（（5,5））（DL）= dlpack.to_dlpack（t）的

DLManagedTensor * toDLPack（常量张量＆SRC）{ATenDLMTensor * atDLMTensor（新ATenDLMTensor）;atDLMTensor->手柄= SRC;atDLMTensor-> tensor.manager_ctx = atDLMTensor;atDLMTensor-> tensor.deleter =＆删除器;atDLMTensor-> tensor.dl_tensor.data = src.data_ptr（）;的int64_t DEVICE_ID = 0;如果（src.type（）is_cuda（）。）{DEVICE_ID = src.get_device（）;} atDLMTensor-> tensor.dl_tensor.ctx = getDLContext（src.type（），DEVICE_ID）;atDLMTensor-> tensor.dl_tensor.ndim = src.dim（）;atDLMTensor-> tensor.dl_tensor.dtype = getDLDataType（src.type（））; atDLMTensor->tensor.dl_tensor.shape = const_cast(src.sizes().data()); atDLMTensor->tensor.dl_tensor.strides = const_cast(src.strides().data()); atDLMTensor->tensor.dl_tensor.byte_offset = 0; return &(atDLMTensor->tensor); }

– Christian S. Perone

## 隐私保护使用InferSent的嵌入和安全两方计算句子语义相似度

### Privacy-preserving Computation

Formally what we want is to jointly evaluate the following function:

$R = F（A，B）$

Such as the private valuesAandB举行私人到它的唯一拥有者，并在结果r将会known to just one or both of the parties.

It seems very counterintuitive that a problem like that could ever be solved, but for the surprise of many people, it is possible to solve it on some security requirements. Thanks to the recent developments in techniques such as FHE (Fully Homomorphic EncryptionOblivious Transfer,乱码电路, problems like that started to get practical for real-life usage and they are being nowadays being used by many companies in applications such as information exchange, secure location, advertisement, satellite orbit collision avoidance, etc.

### 句子相似度比较

Another approach for this problem (this is the approach that we’ll be using), is to compare the sentences in the sentence embeddings space. We just need to create sentence embeddings using a Machine Learning model (we’ll useInferSent更高版本），然后比较句子的嵌入物。不过，这种做法也引起了另一个问题：如果什么鲍勃或翘火车一Seq2Seq模式，将从对方回项目的大致描述的嵌入物去？

### Generating sentence embeddings with InferSent

They used a Bi-directional LSTM with attention that consistently surpassed many unsupervised training methods such as the SkipThought vectors. They also provide aPytorch implementation我们将用它来生成句子的嵌入。

进口numpy的从NP进口火炬＃训练模型：https://github.com/facebookresearch/Infer金宝博游戏网址Sent GLOVE_EMBS = '../dataset/GloVe/glove.840B.300d.txt' INFERSENT_MODEL = 'infersent.allnli.pickle' ＃负荷训练InferSent模型模型= torch.load（INFERSENT_MODEL，map_location =拉姆达存储，在上述：存储）model.set_glove_path（GLOVE_EMBS）model.build_vocab_k_words（K = 100000）

$cos(\pmb x, \pmb y) = \frac {\pmb x \cdot \pmb y}{||\pmb x|| \cdot ||\pmb y||}$

$cos(\hat{x}, \hat{y}) =\hat{x} \cdot\hat{y}$

# This function will forward the text into the model and # get the embeddings. After that, it will normalize it # to a unit vector. def encode(model, text): embedding = model.encode([text])[0] embedding /= np.linalg.norm(embedding) return embedding

＃此功能将为了缩放嵌入到＃去掉小数点。DEF比例（嵌入）：SCALE = 1 << 14 scale_embedding = np.clip（嵌入，0.0，1.0）* SCALE返回scale_embedding.astype（np.int32）

Now we just need to create some sentence samples that we’ll be using:

＃爱丽丝句子alice_sentences =列表[“我的猫很喜欢我的键盘走了”，“我想爱抚我的猫”，]＃鲍勃的句子bob_sentences名单= [“猫总是走在我的键盘”，]

＃爱丽丝句子alice_sentence1 =编码（型号，alice_sentences [0]）= alice_sentence2编码（型号，alice_sentences [1]）＃鲍勃句bob_sentence1 =编码（型号，bob_sentences [0]）

>>> np.dot(bob_sentence1, alice_sentence1) 0.8798542 >>> np.dot(bob_sentence1, alice_sentence2) 0.62976325

Since we have now the embeddings, we just need to convert them to scaled integers:

# Scale the Alice sentence embeddings alice_sentence1_scaled = scale(alice_sentence1) alice_sentence2_scaled = scale(alice_sentence2) # Scale the Bob sentence embeddings bob_sentence1_scaled = scale(bob_sentence1) # This is the unit vector embedding for the sentence >>> alice_sentence1 array([ 0.01698913, -0.0014404 , 0.0010993 , ..., 0.00252409, 0.00828147, 0.00466533], dtype=float32) # This is the scaled vector as integers >>> alice_sentence1_scaled array([278, 0, 18, ..., 41, 135, 76], dtype=int32)

### 两方安全计算

In order to perform secure computation between the two parties (Alice and Bob), we’ll use theABY framework。ABY实现了许多差异安全计算方案，并允许你描述你的计算像下面的图片，其中姚明的百万富翁的问题描述描绘的电路：

As you can see, we have two inputs entering in one GT GATE (greater than gate) and then a output. This circuit has a bit length of 3 for each input and will compute if the Alice input is greater than (GT GATE) the Bob input. The computing parties then secret share their private data and then can use arithmetic sharing, boolean sharing, or Yao sharing to securely evaluate these gates.

ABY是很容易使用，因为你可以描述你的输入，股票，盖茨和它会做休息，你如创建套接字通信信道，在需要的时候进行数据交换等。然而，实施完全是用C ++编写，并I’m not aware of any Python bindings for it (a great contribution opportunity).

After that, we just need to execute the application on two different machines (or by emulating locally like below):

＃这将执行的服务器部分，所述-r 0指定的角色（服务器）＃和载体的-n 4096只限定了尺寸（InferSent生成＃4096维的嵌入）。〜＃./innerproduct -r 0 -n 4096＃而另一个进程相同（或另一台机器，但是对于另一个＃机执行，你必须明明指定IP）。〜＃./innerproduct -r 1 -n 4096

alice_sentence1的内积和alice_sentence2的bob_sentence1 = 226691917内产品和bob_sentence1 = 171746521

Even in the integer representation, you can see that the inner product of the Alice’s first sentence and the Bob sentence is higher, meaning that the similarity is also higher. But let’s now convert this value back to float:

>>> SCALE = 1 << 14＃这是点的产品，我们应该得到>>> np.dot（alice_sentence1，bob_sentence1）0.8798542＃这是内部的产品，我们在安全计算>>> 226691917 / SCALE **了2.00.8444931＃这是点的产品，我们应该得到>>> np.dot（alice_sentence2，bob_sentence1）0.6297632＃这是内部的产品，我们在安全计算得到>>> 171746521 / SCALE ** 2.0 0.6398056

– Christian S. Perone

Cite this article as: Christian S. Perone, "Privacy-preserving sentence semantic similarity using InferSent embeddings and secure two-party computation," inTerra Incognita，22/01/2018，//www.cpetem.com/2018/01/privacy-preserving-infersent/


text:
# Talk:Series (mathematics)

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 Definition:  A sequence of numbers defined by the partial sums of another infinite sequence. [d] [e]

## Sigma?

The former uses \Sigma ; the latter uses \sum . Michael Hardy 14:39, 11 April 2007 (CDT)

## Taylor series

Do we include stuff about Taylor series in this article, or start another one about Taylor series? Yi Zhe Wu 16:41, 21 July 2007 (CDT)

Of course Taylor series deserves an article — and enjoys one, BTW. Surely, it should be briefly announced/linked in the present article, as well as Fourier series. My idea is to go through some convergence criteria as this is the very first task of the analysis and the "motivations" section prepared the ground for this. Next, pass to particularly important cases like power/Taylor series or Fourier one. --Aleksander Stos 17:10, 21 July 2007 (CDT)
Nice, and good job too! I learned about Taylor series this year, but not Fourier series. Best. Yi Zhe Wu 18:50, 21 July 2007 (CDT)

## Ratio vs root test

I'm not so sure what the last paragraph wants to say. It may happen that the ratio test does not give an answer, because the limit of ratios does not exist, while the root test shows convergence or divergence. Example: the series 1 + 1 + 1/2 + 1/2 + 1/4 + 1/4 + 1/8 + 1/8 + 1/16 + 1/16 + … Also, the limes superior (lim sup) should perhaps be explained? -- Jitse Niesen 21:14, 22 August 2007 (CDT)

Right you are! I meant that we obtain the same limit L in both cases (when it exists) and the choice between the two criteria is of practical/computational nature, just like you indicate. It was far from being clear. Please fix as you like, otherwise I'll fix it today. Aleksander Stos 02:04, 23 August 2007 (CDT)

I reworked the bad text. On reflection, maybe the \limsup should be simply turned into the \lim? I mean that this is the basic ("most popular") version -- and for ratio test I used a similar approach (there are some limsup/liminf formulations for ratio test as well). I think refinements can be presented in separate articles on tests, here we would adopt basic versions. if no objection appears I'll introduce the simplification. Aleksander Stos 11:32, 23 August 2007 (CDT)

PS Thanks for copy editing.

## Clarify what is being summed

It seems to me that the page dances around precisely which numbers are being added. For instance, in the formal definition section, it refers only to "elements that can be added", thereby leaving the possibility of consideration of series of rational numbers, real numbers, complex numbers, p-adic numbers, and more generally, elements of a topological group of some sort. However, in the discussion of alternating series, it says that the elements in a series can change sign, tacitly assuming that the series are now series of real numbers. Clearly, the series that would be found most interesting to a general audience are series of real numbers. However, in writing up the Riemann zeta function page, I pointed out that to understand the definition, one must understand infinite series of complex numbers, so these should be addressed on some page.

It seems to me that addressing this issue would require some sound organizational thought, and then possibly some serious revision of the present article. Any suggestions for the "best" way to approach this issue? Barry R. Smith 21:28, 27 March 2008 (CDT)

## Geometric series

I am trying to draft an article on Banking with a simple explanation of the money-generating capacity of fractional-reserve banking. It would be a help if I could refer the reader to a paragraph in this article explaining the idea of the sum of an infinite geometric series.Nick Gardner 10:09, 6 November 2008 (UTC)

See Geometric series.--Paul Wormer 11:24, 6 November 2008 (UTC)

## Not the only sort of series in mathematics

I wonder whether Series (mathematics) is quite appropriate for this topic, as opposed to, say, analysis or calculus. There is also the concept of series in group theory which I'm hoping to start, together with the related iconcepts in Lie algebras and lattices, not to mention time series in probability and statistics. I would suggest moving to Series (analysis) and that this article say something like

In mathematics, series may refer to

Richard Pinch 07:27, 7 November 2008 (UTC)

Out of curiosity: what is the difference in group theory between a chain, sequence, and a series? (This is not a rhetoric question, I often wondered). --Paul Wormer 08:27, 7 November 2008 (UTC)
Sequence of subgroups implies simply being indexed by natural numbers; chain implies ordered by subgroup inclusion as well; series is the term of art. Richard Pinch 18:53, 7 November 2008 (UTC)
I'm sorry, I don't get it, what do you mean by "term of art"? --Paul Wormer 08:07, 8 November 2008 (UTC)
I mean that series is the term used by the practitioners of the art of group theory. Richard Pinch 12:37, 8 November 2008 (UTC)