text:
# Problem w/ Windows 10 indexing .odt content for File Explorer search function

My LibreOffice version is 4.4.5.2 and I am using 64-bit Windows 10. The language of each is English and the only component I am really concerned with for this is Writer.

Here is the issue: My File Explorer searches fail to turn up valid results of .odt content. Although others have run into problems similar to mine, I felt my situation was unique enough (and I was unable to find a solution from other threads) to warrant asking this question anew. The closest case to mine I could find was this from one of our OpenOffice chums, but it unfortunately proved unhelpful because of the poster's good fortune.

I have ensured that the folder within which I am searching has the proper settings (specifically by making sure "Allow files in this folder to have contents indexed in addition to file properties" is checked). Under Windows 10's Indexing Options, I have ensured that the proper directory is indexed (which I also rebuilt), and under the Advanced menu in the File Types tab, I have ensured that .odt is checked and its radio button for "Index Properties and File Contents" is selected. None of these has solved the problem.

With indexing turned on, conducting File Explorer searching for content in the formats of .docx and .txt has been successful--it's just the .odt file format which seems to have a problem. However, searching for the words in the title of .odt files has turned up accurate results. I know that the .odt file content is not being indexed because when I disable relying on the index for the File Explorer searches, the content from .odt files will actually turn up in subsequent searches.

Some who ran into this problem in the past used something called IFilter, which I'm honestly not very familiar with, but it seems to have become outdated and unsuitable since Windows 8. I couldn't find much of anything in a cursory search of IFilter in conjunction with Windows 10, which has only strengthened my suspicion that it is not a viable path.

I appreciate any and all help to assist me in resolving this problem. It has proven both resilient and frustrating so far, but I cling to the hope that this foe will yet be conquered!

edit retag close merge delete

Sort by » oldest newest most voted

Hi Lone Peregrine

This is the M$info on iFilters; it's unlikely to help you: https://msdn.microsoft.com/en-us/library/windows/desktop/dd940431%28v=vs.85%29.aspx I think that this reply from answers.microsoft.com may help: The OST is not crawled by the indexer as other files are. Rather the indexer requests content from Outlook via URI and then indexes the results. [Note: "OST" refers to '.ost' files, which are "Offline Outlook files"] The possible clue as to how to do this comes at this lifehacker article ("Choose Which File Extensions Can Be Searched By Content"): 1. go to the Start Menu 2. search for "Indexing Options" 3. Choose the top result that comes up and then click the Advanced button 4. Under the File Types tab, add ODT to the list (if not already there) (it will need to be connected to LO as the program that it is associated with, as to be used with ODT files in the same way that Outlook is used with OST files) ## Extra: The ODT, ODS, etc. files are all simple Zip files + can be opened by any standard ZIP app. If the above does not work, then--in the absence of a proper iFilter for the file--connecting it as a ZIP file may also work. If this helps then please tick the answer (✔) ...and/or show you like it with an uptick () more ## Comments As I wrote in the original post, I've already done what you described concerning Indexing Options. Right now the only successful option is simply to disable using the index for searches. ( 2015-11-27 06:23:18 +0100 )edit I have this same problem, although you can see that I have asked for a different solution here. I have a question for Alex, or anyone else who might know. Above, Alex says to associate LO files, now associated with the "Plain Text Filter", with LO or an unziper. How? My files are correctly associated to open on a click, but I've found nothing to change the filter settings, and I've looked hard. ( 2017-10-22 05:47:07 +0100 )edit Hi Lone Peregrine! This info is not an answer to the exact question you asked, but it did helped me with a very similar problem. The Copernic desktop search seems to index and find OO, LO, and MS files with comparable ease. I am still using the free version, with an annoying file number limit (75,000) that only amounts to about a fifth of my files, but by concentrating the bulk of my LO files in a few directories and excluding most of the others I've been able to make do with a two search systems solution. It is a kludge, and sooner or later I'll solve the Windows search problem or buy the full Copernic license ($35, single user). But in the meantime I suspect you might find it an improvement over unindexed search.

It's too bad it, or something like it (DocFetcher? I also spent some time using DF -- lightning-fast, very capable (RegEx! Take that, Windows1), but with an interface that is less intuitive and harder to use) can't just be bundled with LO. If it can't. Maybe LO's front end/user experience gurus could build a better interface to the DocFetcher back end?

Just a thought.

more


text:
Journal topic
Proc. IAHS, 382, 851–855, 2020
https://doi.org/10.5194/piahs-382-851-2020
Proc. IAHS, 382, 851–855, 2020
https://doi.org/10.5194/piahs-382-851-2020

Pre-conference publication 07 May 2020

Pre-conference publication | 07 May 2020

# Developing a digital platform for knowledge disclosure of land subsidence

Developing a digital platform for knowledge disclosure of land subsidence
Hiddo Velsink1, Ursula Backhausen1, and Geert J. Roovers2 Hiddo Velsink et al.
• 1Research Group Digital Smart Services, Utrecht University of Applied Sciences, Utrecht, P.O. Box 182, 3500 AD, the Netherlands
• 2Research Group Subsurface Issues, Saxion University of Applied Sciences, Enschede, P.O. Box 70000, 7500 KB, the Netherlands

Correspondence: Hiddo Velsink (hiddo.velsink@hu.nl)

Abstract

Land subsidence in areas with weak soils affects a large part of the Netherlands and causes many problems. To solve them diverse and specialized knowledge of possible measures to prevent, mitigate or reverse land subsidence is needed. This knowledge is fragmented over many agencies, companies and individuals. Here we show how data and knowledge are related and we stress the importance of implicit knowledge for knowledge transfer on land subsidence. It is demonstrated that land subsidence in the Netherlands is a “wicked problem”. This makes its solution cumbersome. However, we show that self-learning digital environments can help considerably in knowledge acquisition, storage and retrieval. We give an inventory of research questions that have still to be answered to make an digital environment really effective for a wicked problem like land subsidence.

1 Introduction

In the Netherlands, significant land subsidence takes place in areas with “weak soils” (peat and clay soils) (Fig. 1). The need to tackle the problem is big.

Figure 1Estimation of land subsidence in the Netherlands 2016–2050 (Klimaateffectatlas, 2017).

Several public authorities in the Netherlands on state, provincial and municipality level have taken initiatives to improve knowledge and knowledge dissemination on land subsidence, for example by: the establishment of the Platform Slappe Bodem (weak soils platform), a collaboration of twenty municipalities and six water boards (in 2015); the launch of the National Knowledge Program on Land Subsidence by several public authorities (in 2016), which started many so-called “knowledge expeditions” in 2018 and 2019; the inclusion of land subsidence in the Inter-administrative Program (in February 2018) and in the Delta Program on Spatial Adaptation (in September 2018) by the national government; and, finally, the deal on the Green Heart Region between the government and several public authorities (in November 2018). These initiatives show that dealing with land subsidence is socially and administratively urgent for the Netherlands.

Knowledge and experience with regard to land subsidence is widely available in the Netherlands, at public authorities, knowledge institutions and engineering firms. They are available in the form of reports, digital tools and the knowledge and experience of experts. However, recording and dissemination are not performed in a structured manner (Twynstra Gudde, 2018; Witteveen+Bos, 2016). Existing knowledge and experience is often fragmentarily available, which makes them difficult to disclose to all potentially interested parties. This makes it difficult to apply adequate solutions for land subsidence problems (Twynstra Gudde, 2018). This situation is experienced in the Netherlands as problematic for professional practice. In addition, new knowledge is developed rapidly and new experiences are gained continuously. This problem gave rise to research on how this problematic disclosure of knowledge on land subsidence in the Netherlands could be tackled. Furthermore, public authorities asked how a digital platform or tool could facilitate such knowledge disclosure.

This article describes the first results of this research and defines resulting new research questions. The research was carried out in the period 2017–2018 based on three components: (1) extensive desk research on theoretical international literature and practical publications in the Netherlands, (2) three bachelor student projects, and (3) five working sessions with professionals in the field of land subsidence in the Netherlands.

This article first describes the theoretical basis of knowledge and knowledge disclosure on land subsidence. Subsequently it describes the situation in professional practice in the Netherlands and analyses this situation. Finally conclusions are drawn and suggestions for further research identified.

2 Knowledge disclosure on land subsidence

## 2.1 Land subsidence

Land subsidence in peat and clay soils occurs in six of the twelve provinces of the Netherlands. The expected subsidence until 2050 varies from a few centimeters to two meters. This subsidence is the result of centuries of interventions in the soil and water system (Van den Born et al., 2016; Erkens et al., 2015; Seijger and Verheijen, 2015). Land subsidence due to natural causes (tectonic earth movements, sedimentation and compression) is often limited to a few millimeters per year. Land subsidence due to human causes (compression, drainage and oxidation) can amount to decimeters per year (Erkens et al., 2015).

Land subsidence has five possible consequences (Erkens et al., 2015; Pieterse et al., 2015): (1) increased flood risks, (2) damage to buildings, foundations and infrastructure, (3) pressure on land use, including the possible disappearance of the peat meadow landscape, (4) increased CO2 emissions, influencing climate change, and (5) increasingly complex water management.

The Netherlands Environmental Assessment Agency calculated that land subsidence will cost society 22 billion euros until 2050 (Van den Born et al., 2016).

Effective governance of land subsidence in the Netherlands is difficult (van Buuren et al., 2017; Erkens et al., 2015; van Hardeveld et al., 2014; Seijger and Verheijen, 2015; Witteveen+Bos, 2016): (1) Subsidence is a creeping process, and therefore difficult to see; (2) The soil structure is heterogeneous and uncertain. As a result, there is uncertainty about the effectiveness of measures; (3) Local spatial differences require customization and differentiation; (4) The costs and benefits are skewed: government agencies pay for a significant part of the costs, while citizens and entrepreneurs enjoy the benefits. (5) The responsibilities are fragmented and the issues transcend administrative and organizational boundaries. The state, provinces, municipalities, water boards and utility companies have to work together, often with different perspectives on the issue. (6) Residents and entrepreneurs are responsible for tackling problems for their homes and land. They have, however, a limited awareness of the consequences of land subsidence and their responsibility therein. (7) The role of land subsidence in local assessment processes: in general, soil conditions are considered to be a technical problem that requires a technical solution.

Land subsidence can, therefore, be seen as a “wicked problem” (Erkens et al., 2015; Rittel and Webber, 1973). A problem is wicked, if (1) it is intertwined with various related problems and knowledge fields, if (2) many different stakeholders with their own interests are involved, with different – often conflicting – perceptions and insights, and if (3) the problem has major consequences. This means that a detailed elaboration and application of measures is not sufficient. Dealing with land subsidence requires a learning, interactive approach, aimed at a coherent action perspective in which the complexity of land subsidence is given a place and parties work together to be effective (Grin et al., 2010; Levin et al., 2012; Metze and Turnhout, 2015).

## 2.2 Data, information and knowledge

To disclose knowledge requires a distinction between data, information and knowledge (Baumard, 1999; Nonaka and Takeuchi, 1995; Weggeman, 2000). Data is data that has not yet been given meaning. Information is data that has been given meaning and that is recorded in documents, information systems and/or networks. This is called explicit knowledge. It remains in an organization when all people are gone. Implicit knowledge (also known as experiential knowledge or tacit knowledge) is knowledge that a person has acquired through the combination of explicit knowledge and experience. This knowledge is not explicitly available in a document. Implicit knowledge is no longer present in an organization when people have left. Weggeman (2000) uses the relation $K=f\left(I,E,S,A\right)$. Knowledge (K) is a function of Information (I), Experience (E), Skills (S) and Attitude (A). Information therefore only becomes knowledge when it is enriched with experience, skills and attitude. Implicit knowledge plays a (still) large(r) role within a “wicked problem” context; experience and learning are even more important. This means that unlocking knowledge on land subsidence – and a digital environment that supports this – must be about unlocking explicit knowledge as well as unlocking implicit knowledge.

## 2.3 Disclosing explicit knowledge

Finding, disclosing and using explicit knowledge on land subsidence, using a digital environment, has to take account of four points: availability, uncertainty, accessibility and reliability of knowledge (Cash et al., 2003; Koppenjan and Klijn, 2004; Lavis et al., 2003). These four points are explained here: (1) Availability: is the knowledge you need already present? (2) Uncertainties: which uncertainties are there? Not only with regard to knowledge, but also with regard to underlying assumptions/different calculation methods/models. (3) Accessibility: is there any knowledge at all about a specific theme? Is it accessible/available? And if so, how much energy (transaction costs) must be invested in acquiring this knowledge? (4) Usefulness of knowledge: knowledge must be relevant, credible and legitimate for this purpose.

## 2.4 Disclosing implicit knowledge

Implicit knowledge is crucial for interpreting a wicked problem and finding an appropriate solution (Baumard, 1999; de Bruijn, 2008; Koppenjan and Klijn, 2004; Nonaka and Takeuchi, 1995; Weggeman, 2000). Implicit knowledge requires personal mechanisms and interaction to be shared (Carrillo et al., 2006). These mechanisms often translate into consultation moments, workshops, training courses, mentoring, etc. (Argote and Ingram, 2000; Goh, 2002). Experimental instruments such as semi-structured interviews, stories and films are used to record implicit knowledge.

## 2.5 Use of digital environments

Digital environments can be used to improve knowledge transfer (Twynstra Gudde, 2018). Digital environments are (mostly) concerned with explicit knowledge, which is preserved, stored and shared via databases, intranet and digital platforms. In recent decades there has been a strong development in these facilities (Schindler, 2002). As they develop, it becomes increasingly easier, faster, more effective and more efficient to communicate and share knowledge, both inside and between organizations (Schindler, 2002). In addition, more people have easy access to knowledge.

To include implicit knowledge in a digital environment, the experimental instruments, mentioned in the previous section, are suitable, provided that the recordings are made searchable.

In recent decades, there has been a rise in self-learning digital systems (machine learning). These systems enable efficient searching and management of large – and ever-increasing – amounts of knowledge, fragmented across many sources (Diakopoulos, 2014; Domingos, 2015; Hosmer et al., 2013; Quinlan, 2014; Singh et al., 2019; Stanley, 2017; Witten et al., 2016).

Self-learning systems collect very many results and recognize patterns in them, whose parameters are used to make predictions for new situations. Using self-learing systems, intelligence can be built into the digital environment (Domingos, 2015; Käfer and Harth, 2018; Stanley, 2017; Witten et al., 2016): (1) Intelligence to find the right terms and concepts in reports and texts and store them via “linked data” (data stored on the internet in a standardized way and provided with a unique URL). (2) Intelligence to perform calculations and monitoring, for example of expected land subsidence.

3 Analysis

Based on the previous sections, one can distinguish four essential issues concerning disclosure of knowledge on land subsidence:

1. Governance of land subsidence is difficult, involving different stakeholders, issues and levels, in which stakeholders have different perceptions. There is no such thing as “one” or “best” solution.

2. Land subsidence is a wicked problem, and thus asks for a learning approach.

3. Knowledge consists of data, information (explicit knowledge) and implicit knowledge. All these aspects have to be addressed. Especially implicit knowledge asks for face-to-face interaction to enable disclosure.

4. Digital environments, capable of self-learning, are crucial to support an effective disclosure of knowledge, but always in coherence with face-to-face learning.

These four issues have to be tackled before one can arrive at a successful digital platform for knowledge disclosure of land subsidence. This has several consequences. A supporting digital environment must focus on unlocking both explicit knowledge and implicit knowledge. To this end, the digital environment must take account of the availability, uncertainties, accessibility and reliability of explicit knowledge. The digital environment must function within a learning network of parties that support each other and must work together to cope with land subsidence. From the perspective of knowledge impact between organizations, it can be concluded that knowledge arises in and works through networks of organizations and around practical cases, where everyone uses and produces knowledge. This means that it is not only important to have support from a digital network, when searching for and finding the right knowledge, but also to easily record available knowledge in the digital network. In addition, knowledge transfer depends on the presence of a knowledge infrastructure (ICT), the time pressure, the organizational culture, the working method of the management and the way in which the parties involved work together. The process of knowledge transfer depends on the personal motives and the mutual relationship between the knowledge transferors. Furthermore, the uptake and use of knowledge in an organization depends on the incentive to acquire new knowledge, the absorption capacity of the organization, the organizational structure and the availability of knowledge reservoirs. Finally, a digital environment that supports the dissemination of knowledge for land subsidence must itself also be learning, so that it can increasingly and effectively respond to the user's question and interpretation of this question in the context of the wicked land subsidence problem. In addition, efficient searching for, and management of, the large – and ever increasing – amount of knowledge, fragmented across many sources, also requires a smart and self-learning digital environment. Such a system uses insights in the field of machine learning and self-learning algorithms. These requirements for access to knowledge and the use of a digital environment, in particular with regard to the role in the learning network and the interpretation of the question in the context of a wicked problem, mean that the digital environment goes beyond what is called a knowledge system or expert system in current literature.

4 Conclusions

Question: How can the problematic disclosure of knowledge on land subsidence in the Netherlands be tackled, and how can a digital platform facilitate such knowledge disclosure?

We conclude that: (1) the current knowledge needs of professionals and the current knowledge disclosure process are not clear, (2) there is not yet an adequate digital environment that supports this knowledge disclosure, (3) such a digital environment must support a network of parties, aimed both at unlocking and recording knowledge, (4) such a digital environment must support the search process for implicit and explicit knowledge, and (5) such a supportive digital environment must be self-learning. This leads to the following research question and underlying sub questions:

1. What is the knowledge requirement of professionals regarding land subsidence?

2. How does the current knowledge dissemination process take place (seeking and recording knowledge) regarding land subsidence within the relevant network of parties?

3. How can this knowledge disclosure process be improved?

4. How can a digital environment strengthen this knowledge disclosure process?

5. How can such a digital environment look like?

We will address these questions in future research.

Data availability
Data availability.

No observational data were acquired in this research. All other data can be accessed via the references.

Author contributions
Author contributions.

The research was designed, the necessary data collected and conclusions drawn by all three authors in collaboration. GJR wrote the first set-up of the article, UB and HV made comments and suggested improvements. Finally HV rearranged and translated the article, sharpened statements and conclusions and made the article comply with the requirements of TISOLS.

Competing interests
Competing interests.

The authors declare that they have no conflict of interest.

Special issue statement
Special issue statement.

This article is part of the special issue “TISOLS: the Tenth International Symposium On Land Subsidence – living with subsidence”. It is a result of the Tenth International Symposium on Land Subsidence, Delft, the Netherlands, 17–21 May 2021.

References

Argote, L. and Ingram, P.: Knowledge Transfer: A Basis for Competitive Advantage in Firms, Organ. Behav. Hum. Dec., 82, 150–169, 2000.

Baumard, P.: Tacit knowledge in organizations, Sage Publications Ltd, London, https://doi.org/10.4135/9781446217375, 1999.

Carrillo, P. M., Robinson, H. S., Anumba, C. J., and Bouchlaghem, N. M.: A knowledge transfer framework: The PFI context, Constr. Manag. Econ., 24, 1045–1056, 2006.

Cash, D. W., Clark, W. C., Alcock, F., Dickson, N. M., Eckley, N., Guston, D. H., Jäger, J., and Mitchell, R. B.: Knowledge systems for sustainable development, P. Natl. Acad. Sci. USA, 100, 8086–8091, 2003.

de Bruijn, H.: Managers en professionals. Over management als probleem en als oplossing, Boom uitgevers Amsterdam, 2008.

Diakopoulos, N.: Algorithmic accountability reporting: On the investigation of black boxes, Tow Center for Digital Journalism, Columbia University, 2014.

Domingos, P.: The master algorithm, Basic Books, New York, 2015.

Erkens, G., Bucx, T., Dam, R., De Lange, G., and Lambert, J.: Sinking coastal cities, Proceedings of the International Association of Hydrological Sciences, 372, 189, 2015.

Goh, S. C.: Managing effective knowledge transfer: An integrative framework and some practice implications, J. Knowl. Manag., 6, 23–30, 2002.

Grin, J., Rotmans, J., and Schot, J.: Transitions to sustainable development: New directions in the study of long term transformative change, Routledge, New York/London, 2010.

Hosmer, D. W., Lemeshow, S., and Sturdivant, R. X.: Applied Logistic Regression, 3rd Edn., Wiley, New Jersey, 2013.

Käfer, T. and Harth, A.: Specifying, monitoring, and executing workflows in linked data environments, in: The Semantic Web – ISWC 2018, ISWC 2018. Lecture Notes in Computer Science, Vol. 11136, edited by: Vrandečić, D., Bontcheva, K., Suárez-Figueroa, M. C., Presutti, V., Celino, I., Sabou, M., Kaffee, L.-A., and Simperl, E., 424–440, Springer, Cham., 2018.

Klimaateffectatlas: Deltares, TNO GDN, Wageningen Environmental Research, 2017.

Koppenjan, J. and Klijn, E. H.: Managing Uncertainties in Networks, Taylor and Francis Ltd., New York/London, 2004.

Lavis, J. N., Robertson, D., Woodside, J. M., McLeod, C. B., and Abelson, J.: How can research organizations more effectively transfer research knowledge to decision makers?, Milbank Q., 81–82, 221–248, 2003.

Levin, K., Cashore, B., Bernstein, S., and Auld, G.: Overcoming the tragedy of super wicked problems: Constraining our future selves to ameliorate global climate change, Policy Sci., 45, 123–152, 2012.

Metze, T. and Turnhout, E.: Politiek, participatie en experts in de besluitvorming over super wicked problems, Bestuurskunde, 23, 3–11, 2015.

Nonaka, I. and Takeuchi, H.: The Knowledge-Creating Company, Oxford University Press Inc, Oxford, 1995.

Pieterse, N., Broek, L. van den, Pols, L., and Huitzing, H.: Het Groene Hart in Beeld, Planbureau voor de Leefomgeving, Den Haag, available at: https://www.pbl.nl/sites/default/files/downloads/PBL2015_Het_Groene_Hart_2e_druk_1351_juli2015.pdf (last access: 6 May 2020), 2015.

Quinlan, J. R.: C4.5: programs for machine learning, Elsevier, Amsterdam, 2014.

Rittel, H. W. J. and Webber, M. M.: Dilemmas in a general theory of planning, Policy Sci., 4, 155–169, 1973.

Schindler, M.: Wissensmanagement in der Projektabwicklung, Lohmar, Köln, 2002.

Seijger, C. and Verheijen, E.: Governance handelingsperspectieven voor bodemdaling in Gouda, Deltares, Delft, 2015.

Singh, V., Bano, S., Yadav, A. K., and Ahmad, S.: Feasibility of Artificial Neural Network in Civil Engineering, International Journal of Trend in Scientific Research and Development, 3, 724–728, 2019.

Stanley, J.: Pitfalls of Artificial Intelligence Decisionmaking Highlighted In Idaho ACLU Case, available at: https://www.aclu.org/blog/privacy-technology/pitfalls-artificial-intelligence-decisionmaking-highlighted-idaho-aclu-case (last access: 6 May 2020), 2017.

Twynstra Gudde: Context – en probleemanalyse voor kennisdoorwerking. Uitvoeringsprogramma Bodem en Ondergrond, Twynstra Gudde, Amersfoort, the Netherlands, 2018.

van Buuren, A., Bil, J. A., and Roovers, G. J.: Styles of public asset management in Dutch regional water management, in: 5th International Symposium on Life-Cycle Engineering, IALCCE 2016, edited by: Bakker, J., Frangopol, D. M., and van Breugel, K., 567–574, Taylor and Francis Group, Delft, the Netherlands, 2017.

Van den Born, G. J., Kragt, F., Henkens, D., Rijken, B., Van Bemmel, B., and Van der Sluis, S.: Dalende bodems, stijgende kosten, PBL report 1064, Planbureau voor de Leefomgeving, Den Haag, the Netherlands, 2016.

van Hardeveld, H., van der Lee, M., Strijker, J., van Bokhoven, A., and de Jong, H.: Toekomstverkenning Bodemdaling; eindrapport fase 1, Hoogheemraadschap De Stichtse Rijnlanden, Provincie Utrecht, Provincie Zuid-Holland, available at: https://www.veenweiden.nl/wp-content/uploads/2015/07/Eindrapport-Toekomstverkenning-bodemdaling-fase-1.pdf (last access: 6 May 2020), 2014.

Weggeman, M. C. D. P.: Kennismanagement: de praktijk, Scriptum Management, Schiedam, the Netherlands, 2000.

Witten, I. H., Frank, E., Hall, M. A., and Pal, C. J.: Data Mining: Practical Machine Learning Tools and Techniques, Elsevier Inc., Amsterdam, the Netherlands, 2016.

Witteveen+Bos: Kennisagenda Slappe Bodem. Inventarisatie en invulling kennisagenda Slappe Bodem, Witteveen+Bos, Deventer, the Netherlands, 2016.

format: plain


text:
# Balance of Payments: Concept and Derivation

## Introduction

The balance of payments is a systematic record of all economic transactions between residents of one country and the rest of the world over a specified period, typically a year. It can be affected by factors such as changes in exchange rates, trade policies, and global economic conditions. The balance of payments is an essential indicator of a country's economic health and can influence its currency's value and ability to borrow from international markets.

## Components of BoP

BoP is divided into three main categories: the current account, the capital account, and the financial account.

The current account includes transactions related to the trade of goods and services, income from investments, and unilateral transfers such as foreign aid. The balance of trade, which represents the difference between a country's exports and imports, is a major component of the current account. A surplus on the current account means that a country is a net lender to the rest of the world, while a deficit means it is a net borrower.

The capital account includes transactions related to the purchase and sale of non-produced, non-financial assets such as patents, copyrights, and trademarks. It also includes capital transfers, such as debt forgiveness and inheritances.

The financial account includes transactions related to the purchase and sale of financial assets, such as stocks, bonds, and foreign currency. It also includes foreign direct investment, which is the ownership of a company or assets in a foreign country, and portfolio investment, which is the purchase of stocks and bonds in foreign companies. A surplus on the financial account means that a country is investing more abroad than it is receiving in foreign investment, while a deficit means the opposite.

## Mathematical derivation

The mathematical derivation rests on few assumptions, such as current accounts incorporate imports and exports of goods only, capital accounts incorporate capital inflows and outflows only, and the capital account is fully convertible.

Capital outflows

$H = \alpha - \beta r ---(i)$

Current accounts balance

$NX=X-M$

$NX=\bar{X} - \gamma - \lambda Y$ [$\theta = \bar{X}-\gamma$]

$NX =\theta - \lambda Y ---(ii)$

External sector equilibrium

$H=NX---(iii)$

Here,

H, NX, Y, and r represent capital outflows, net exports, national income, and rate of interest respectively. $\beta$ represents the interest elasticity of capital outflows and $\lambda$ is income elasticity of imports. Exports depend upon foreign countries' economies, so it is exogenously determined.

Now,

From Equation (iii),

$H=NX$

$\alpha - \beta r = \theta - \lambda Y$

$r = \frac{\alpha - \theta}{\beta} + \frac{\lambda}{\beta}Y---(1)$

Equation (1) represents the upward-sloping Balance of Payments curve.

The slope of BoP curve:  $\frac{\lambda}{\beta}$

Intercept of BoP curve: $\frac{\alpha - \theta}{\beta}$

The slope of BoP curve

The slope of BoP curve depends upon the slope of the capital outflow function and net exports function. If the slope of the net exports function, that is marginal propensity to imports, increases, then the slope of the BoP curve also increases thereby steepening the BoP curve. Likewise, the increase in interest elasticity of capital will decrease both slope and intercept. Consequently, the new BoP curve will be flatter and lie below the original BoP curve.

The shift in BoP curve

The shift in BoP curve depends upon $\alpha, \beta$, and $\theta$. An increase in either $\theta$ or $\beta$ or both will decrease the intercept thereby shifting the BoP curve downward. While an increase in $\alpha$ will increase the intercept thereby shifting the BoP curve upward. This intercept of BoP curve depends upon the slope and intercept of capital function, and the slope of the net exports function.


text:
# naginterfaces.library.blas.ztfsm¶

naginterfaces.library.blas.ztfsm(transr, side, uplo, trans, diag, alpha, a, b)[source]

ztfsm performs one of the matrix-matrix operations

where is a complex triangular matrix stored in Rectangular Full Packed (RFP) format, is an complex matrix, and is a complex scalar. denotes or equivalently .

No test for singularity or near-singularity of is included in this function. Such tests must be performed before calling this function.

For full information please refer to the NAG Library document for f06wp

https://www.nag.com/numeric/nl/nagdoc_28.7/flhtml/f06/f06wpf.html

Parameters
transrstr, length 1

Specifies whether the normal RFP representation of or its conjugate transpose is stored.

The matrix is stored in normal RFP format.

The conjugate transpose of the RFP representation of the matrix is stored.

sidestr, length 1

Specifies whether is operated on from the left or the right, or similarly whether (or its transpose) appears to the left or right of the solution matrix in the linear system to be solved.

is pre-multiplied from the left. The system to be solved has the form or .

is post-multiplied from the right. The system to be solved has the form or .

uplostr, length 1

Specifies whether is upper or lower triangular.

is upper triangular.

is lower triangular.

transstr, length 1

Specifies whether the operation involves or , i.e., whether or not is transpose conjugated in the linear system to be solved.

The operation involves , i.e., is not transpose conjugated.

The operation involves , i.e., is transpose conjugated.

diagstr, length 1

Specifies whether has nonunit or unit diagonal elements.

The diagonal elements of are stored explicitly.

The diagonal elements of are assumed to be , the corresponding elements of are not referenced.

alphacomplex

The scalar .

acomplex, array-like, shape

Note: the required length for this argument is determined as follows: if : ; if : ; otherwise: .

, the triangular matrix if or the triangular matrix if , stored in RFP format (as specified by ). The storage format is described in detail in the F07 Introduction. If , is not referenced.

bcomplex, array-like, shape

The matrix .

If , need not be set.

Returns
bcomplex, ndarray, shape

The updated matrix , or similarly the solution matrix .

Raises
NagValueError
(errno )

On entry, error in parameter .

Constraint: or .

(errno )

On entry, error in parameter .

Constraint: or .

(errno )

On entry, error in parameter .

Constraint: or .

(errno )

On entry, error in parameter .

Constraint: or .

(errno )

On entry, error in parameter .

Constraint: or .

(errno )

On entry, error in parameter .

Constraint: .

(errno )

On entry, error in parameter .

Constraint: .

Notes

No equivalent traditional C interface for this routine exists in the NAG Library.

ztfsm solves (for ) a triangular linear system of one of the forms

where is a complex triangular matrix stored in RFP format, , are complex matrices, and is a complex scalar. The RFP storage format is described in the F07 Introduction.

References

Gustavson, F G, Waśniewski, J, Dongarra, J J and Langou, J, 2010, Rectangular full packed format for Cholesky’s algorithm: factorization, solution, and inversion, ACM Trans. Math. Software (37, 2)


text:
If |x|>3, which of the following must be true? : GMAT Problem Solving (PS) - Page 2
Check GMAT Club Decision Tracker for the Latest School Decision Releases https://gmatclub.com/AppTrack

 It is currently 27 Feb 2017, 19:24

### GMAT Club Daily Prep

#### Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# If |x|>3, which of the following must be true?

Author Message
TAGS:

### Hide Tags

VP
Status: Far, far away!
Joined: 02 Sep 2012
Posts: 1123
Location: Italy
Concentration: Finance, Entrepreneurship
GPA: 3.8
Followers: 184

Kudos [?]: 2000 [0], given: 219

Re: If |x| > 3 , which of the following must be true? [#permalink]

### Show Tags

13 May 2013, 01:17
Archit143 wrote:
I too have the same doubt...can anyone address the query

Archit

The question asks is $$x>3$$ or $$x<-3$$?

III tells us that $$x>3$$ or $$x<-1$$. So is $$x>3$$ or $$x<-3$$? YES

$$x>3$$ from question => $$x>3$$from III: Correct
$$x<-3$$ from question => $$x<-1$$ from III: Correct as well. We are asked if x<-3 and III tells us that x<-1 so for sure it will be <-3 also.

Hope it's clear now!
_________________

It is beyond a doubt that all our knowledge that begins with experience.

Kant , Critique of Pure Reason

Tips and tricks: Inequalities , Mixture | Review: MGMAT workshop
Strategy: SmartGMAT v1.0 | Questions: Verbal challenge SC I-II- CR New SC set out !! , My Quant

Rules for Posting in the Verbal Forum - Rules for Posting in the Quant Forum[/size][/color][/b]

Veritas Prep GMAT Instructor
Joined: 16 Oct 2010
Posts: 7191
Location: Pune, India
Followers: 2174

Kudos [?]: 14058 [0], given: 222

Re: If |x| > 3 , which of the following must be true? [#permalink]

### Show Tags

13 May 2013, 08:44
danzig wrote:
If $$|x| > 3$$ , which of the following must be true?

I. $$x > 3$$

II. $$x^2 > 9$$

III. $$|x - 1| > 2$$

A. I only
B. II only
C. I and II only
D. II and III only
E. I, II, and III

I don't understand well III. $$|x - 1| > 2$$ is equivalent to $$x > 3$$ or $$x < -1$$. The last inequality ($$x < -1$$ ) includes integers -2 and -3, integers that are not included in one of the original inequalities ( $$x < -3$$ ). How could III be true?

If some numbers confuse you, don't fixate on them. Go ahead and take some other easier examples.
Let's keep the wording of the question same but make it simple.

If n < 6, which of the following must be true?

I.

II.

III. n < 8

Can we say that III must be true? Yes!
If n is less than 6 then obviously it is less than 8 too.
If n is less than 6, it will take values such as -20, 2, 5 etc. All of these values will be less than 8 too.

Values 6 and 7 are immaterial because n cannot take these values. You are given that n is less than 6 so you only need to worry about values that n CAN take. Those should satisfy n < 8.

Similarly, your question says that x > 3 or x < -3

Then we can say that x > 3 or x < -1. All values that will be less than -3 will be less than -1 too.

Check out my post on a similar tricky question : http://www.veritasprep.com/blog/2012/07 ... -and-sets/
_________________

Karishma
Veritas Prep | GMAT Instructor
My Blog

Get started with Veritas Prep GMAT On Demand for $199 Veritas Prep Reviews Intern Joined: 15 Mar 2013 Posts: 5 Followers: 0 Kudos [?]: 0 [0], given: 2 Re: If |x| > 3 , which of the following must be true? [#permalink] ### Show Tags 13 Aug 2013, 12:40 What if x = -2 that is < -1 but > than -3 so IIImust be out?no Zarrolou wrote: Archit143 wrote: I too have the same doubt...can anyone address the query Archit The question asks is $$x>3$$ or $$x<-3$$? III tells us that $$x>3$$ or $$x<-1$$. So is $$x>3$$ or $$x<-3$$? YES $$x>3$$ from question => $$x>3$$from III: Correct $$x<-3$$ from question => $$x<-1$$ from III: Correct as well. We are asked if x<-3 and III tells us that x<-1 so for sure it will be <-3 also. Hope it's clear now! Posted from GMAT ToolKit Senior Manager Joined: 10 Jul 2013 Posts: 335 Followers: 3 Kudos [?]: 323 [0], given: 102 Re: If |x|>3, which of the following must be true? [#permalink] ### Show Tags 13 Aug 2013, 13:27 corvinis wrote: If |x| > 3, which of the following must be true? I. x > 3 II. X^2 > 9 III. |x-1|>2 A. I only B. II only C. I and II only D. II and III only E. I, II, and III I can't understand how the official answer can be right. For me is B. Please respond and I'll provide official explanation! Thanks |x| > 3 means x>3 or x<-3 so I is false because x<-3 is true. II. x^2 > 9 satisfies both equations (use x=-4 or x=5 ) III. is also true for x=-4 and x=5. so D _________________ Asif vai..... Math Expert Joined: 02 Sep 2009 Posts: 37144 Followers: 7274 Kudos [?]: 96810 [0], given: 10786 Re: If |x| > 3 , which of the following must be true? [#permalink] ### Show Tags 13 Aug 2013, 23:56 Expert's post 1 This post was BOOKMARKED rusth1 wrote: If |x| > 3, which of the following must be true? I. x > 3 II. X^2 > 9 III. |x-1|>2 A. I only B. II only C. I and II only D. II and III only E. I, II, and III What if x = -2 that is < -1 but > than -3 so IIImust be out?no Zarrolou wrote: Archit143 wrote: I too have the same doubt...can anyone address the query Archit The question asks is $$x>3$$ or $$x<-3$$? III tells us that $$x>3$$ or $$x<-1$$. So is $$x>3$$ or $$x<-3$$? YES $$x>3$$ from question => $$x>3$$from III: Correct $$x<-3$$ from question => $$x<-1$$ from III: Correct as well. We are asked if x<-3 and III tells us that x<-1 so for sure it will be <-3 also. Hope it's clear now! Posted from GMAT ToolKit x cannot be -2 because we are told that |x|>3, and |-2|=2<3. Hope it helps. _________________ GMAT Club Legend Joined: 09 Sep 2013 Posts: 13994 Followers: 592 Kudos [?]: 168 [0], given: 0 Re: If |x|>3, which of the following must be true? [#permalink] ### Show Tags 28 Oct 2014, 09:53 Hello from the GMAT Club BumpBot! Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos). Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email. _________________ Intern Joined: 17 May 2012 Posts: 49 Followers: 0 Kudos [?]: 9 [0], given: 126 Re: If |x|>3, which of the following must be true? [#permalink] ### Show Tags 23 Nov 2014, 22:46 Hi All, After going through the explanations I could understand why option B was not correct. But I am sure under timed conditions, I might make a similar mistake. Does anyone have a way to solve such problems, so that a mistake can be avoided and an important case like the 3rd option be considered while evaluating answer choices? Thanks, AK Director Joined: 25 Apr 2012 Posts: 728 Location: India GPA: 3.21 WE: Business Development (Other) Followers: 43 Kudos [?]: 708 [0], given: 723 Re: If |x|>3, which of the following must be true? [#permalink] ### Show Tags 23 Nov 2014, 23:29 aj0809 wrote: Hi All, After going through the explanations I could understand why option B was not correct. But I am sure under timed conditions, I might make a similar mistake. Does anyone have a way to solve such problems, so that a mistake can be avoided and an important case like the 3rd option be considered while evaluating answer choices? Thanks, AK Hi AK, Why will you leave an option out...that's a big no...in this question St 2 is true so you can remove answer options which don't have st 2 as one of the option and see if it reduces your work load... You may want to refresh some basics on how to go about solving such questions.. This is why we need to practice and see where we are going wrong...For instance this is an important pointer for you to never to overlook an option.. Check out below link: math-absolute-value-modulus-86462.html _________________ “If you can't fly then run, if you can't run then walk, if you can't walk then crawl, but whatever you do you have to keep moving forward.” Intern Joined: 17 May 2012 Posts: 49 Followers: 0 Kudos [?]: 9 [0], given: 126 Re: If |x|>3, which of the following must be true? [#permalink] ### Show Tags 23 Nov 2014, 23:43 Thanks WondedTiger, Maybe I didn't present my question correctly. I didn't leave the 3rd option but came to the conclusion that it was wrong and chose my answer as B. I just want to prevent that in timed conditions for difficult questions like these, which have subtle differences that makes an answer choice right. Director Joined: 25 Apr 2012 Posts: 728 Location: India GPA: 3.21 WE: Business Development (Other) Followers: 43 Kudos [?]: 708 [0], given: 723 Re: If |x|>3, which of the following must be true? [#permalink] ### Show Tags 23 Nov 2014, 23:53 aj0809 wrote: Thanks WondedTiger, Maybe I didn't present my question correctly. I didn't leave the 3rd option but came to the conclusion that it was wrong and chose my answer as B. I just want to prevent that in timed conditions for difficult questions like these, which have subtle differences that makes an answer choice right. hmm.. Did you solve the 3rd option correctly or you made it a mistake. Identify the step where you made the mistake.. Consider making an error log..That will certainly help... _________________ “If you can't fly then run, if you can't run then walk, if you can't walk then crawl, but whatever you do you have to keep moving forward.” Intern Joined: 18 May 2014 Posts: 36 GMAT 1: 680 Q49 V35 Followers: 5 Kudos [?]: 33 [0], given: 184 If |x|>3, which of the following must be true? [#permalink] ### Show Tags 22 May 2015, 06:26 III. |x-1|>2 This implies that the distance of x from 1 must be greater than 2. So x is either greater than 3 or less than -1. Now, recall all the values that x can take. For each value, can be say that x is either greater than 3 or less than -1? Yes. 3.00001 - x is greater than 3 3.5 : x is greater than 3 4.2 : x is greater than 3 5.7 : x is greater than 3 67 : x is greater than 3 1000 : x is greater than 3 -3.45 : x is less than -1 -4 : x is less than -1 -8 : x is less than -1 -100 : x is less than -1 For every value that x can take, x will be either greater than 3 or less than -1. Note that we are not saying that every value less than -1 must be valid for x. We are saying that every value that is valid for x (found by using |x| > 3) will be either greater than 3 or less than -1.Hence |x-1|>2 must be true for every value that x can take. VeritasPrepKarishma Thank you for this! I was doing 'must be true' questions wrong! Current Student Joined: 29 May 2013 Posts: 124 Location: India Concentration: Technology, Marketing WE: Information Technology (Consulting) Followers: 0 Kudos [?]: 13 [0], given: 42 Re: If |x|>3, which of the following must be true? [#permalink] ### Show Tags 20 Jun 2015, 01:27 i dont get it...if x=-2, then |x|=2, which does not satisfy the equation, how is it true? Math Expert Joined: 02 Sep 2009 Posts: 37144 Followers: 7274 Kudos [?]: 96810 [0], given: 10786 Re: If |x|>3, which of the following must be true? [#permalink] ### Show Tags 20 Jun 2015, 01:33 jayanthjanardhan wrote: i dont get it...if x=-2, then |x|=2, which does not satisfy the equation, how is it true? Please read the whole thread. x cannot be -2 because we are told that |x|>3, and |-2|=2<3. _________________ Intern Joined: 03 Jul 2015 Posts: 40 Followers: 0 Kudos [?]: 12 [0], given: 27 Re: If |x|>3, which of the following must be true? [#permalink] ### Show Tags 03 Sep 2015, 01:51 SOURH7WK wrote: fameatop wrote: Option3-|x-1|>2, which means (x-1)>2 ---> x>3 (if x-1>0) - True it also means (x-1)<-2---->x<-1 (if x-1<0) X<-1 satisfies x<-3. Thus true Both 2 & 3 is true Thus Answer D Hope it helps Now if I take x=-2 will it satisfy the condition? if in case of iii. i square both of the inequality, then what will be my fault? GMAT Club Legend Joined: 09 Sep 2013 Posts: 13994 Followers: 592 Kudos [?]: 168 [0], given: 0 Re: If |x|>3, which of the following must be true? [#permalink] ### Show Tags 11 Sep 2016, 08:33 Hello from the GMAT Club BumpBot! Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos). Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email. _________________ Manager Joined: 22 Feb 2016 Posts: 112 Location: India Concentration: Economics, Healthcare GMAT 1: 690 Q42 V47 GMAT 2: 710 Q47 V39 GPA: 3.57 Followers: 1 Kudos [?]: 7 [0], given: 208 Re: If |x|>3, which of the following must be true? [#permalink] ### Show Tags 13 Nov 2016, 20:24 Zarrolou wrote: Archit143 wrote: I too have the same doubt...can anyone address the query Archit The question asks is $$x>3$$ or $$x<-3$$? III tells us that $$x>3$$ or $$x<-1$$. So is $$x>3$$ or $$x<-3$$? YES $$x>3$$ from question => $$x>3$$from III: Correct $$x<-3$$ from question => $$x<-1$$ from III: Correct as well. We are asked if x<-3 and III tells us that x<-1 so for sure it will be <-3 also. Hope it's clear now! Still not clear. It is saying MUST be true. Veritas Prep GMAT Instructor Joined: 16 Oct 2010 Posts: 7191 Location: Pune, India Followers: 2174 Kudos [?]: 14058 [0], given: 222 Re: If |x|>3, which of the following must be true? [#permalink] ### Show Tags 24 Nov 2016, 22:53 VeritasPrepKarishma wrote: corvinis wrote: If |x| > 3, which of the following must be true? I. x > 3 II. X^2 > 9 III. |x-1|>2 A. I only B. II only C. I and II only D. II and III only E. I, II, and III I can't understand how the official answer can be right. For me is B. Please respond and I'll provide official explanation! Thanks Responding to a pm: |x| > 3 implies that x is a point whose distance from 0 is more than 3. So x could be greater than 3 or less than -3. Before you move further, think about the values x can take: 3.00001, 3.5, 4.2, 5.7, 67, 1000, -3.45, -4, -8, -100 etc. The only values it cannot take are -3 <= x <= 3 Which of the following must be true? I. x > 3 For every value that x can take, must x be greater than 3? No. e.g. if x takes -3.45, -4 etc, it will not be greater than 3 so this is not true. II. X^2 > 9 This is the same as |x| > 3 so it must be true III. |x-1|>2 This implies that the distance of x from 1 must be greater than 2. So x is either greater than 3 or less than -1. Now, recall all the values that x can take. For each value, can be say that x is either greater than 3 or less than -1? Yes. 3.00001 - x is greater than 3 3.5 : x is greater than 3 4.2 : x is greater than 3 5.7 : x is greater than 3 67 : x is greater than 3 1000 : x is greater than 3 -3.45 : x is less than -1 -4 : x is less than -1 -8 : x is less than -1 -100 : x is less than -1 For every value that x can take, x will be either greater than 3 or less than -1. Note that we are not saying that every value less than -1 must be valid for x. We are saying that every value that is valid for x (found by using |x| > 3) will be either greater than 3 or less than -1. Hence |x-1|>2 must be true for every value that x can take. Responding to a pm: Quote: I couldn't understand the solution for option B. Since |x|>3 we can say that |x|-1>2 ( subtracting 2 from both sides). But how are we saying that |x|-1 is equal to |x-1|. They are not the same: |x - 1| > 2 and |x|-1 > 2 |x - 1| > 2 means x > 3 or x < -1 |x| - 1 > 2 |x| > 3 means x > 3 or x < -3 But not what is given and what is asked. We are GIVEN that |x| > 3 So we KNOW that x is either greater than 3 or it is less than -3. So valid values for x are 3.4, 4, 101, 2398675, -3.6, -5, -78 etc Now the question is: "Is |x - 1| > 2?" "Is x always either greater than 3 or less than -1?" All positive values of x are given to be greater than 3. All negative values of x are given to be less than -3. So obviously they are less than -1 too. Hence, |x - 1| > 2 is true. Helps? _________________ Karishma Veritas Prep | GMAT Instructor My Blog Get started with Veritas Prep GMAT On Demand for$199

Veritas Prep Reviews

Re: If |x|>3, which of the following must be true?   [#permalink] 24 Nov 2016, 22:53

Go to page   Previous    1   2   [ 37 posts ]

Similar topics Replies Last post
Similar
Topics:
4 If √x=x , then which of the following must be true ? 3 26 Oct 2014, 03:35
18 If |x|=−x, which of the following must be true? 5 22 Mar 2014, 01:31
8 If √x = x, then which of the following must be true? 4 21 Mar 2013, 23:56
3 If x-y=8, which of the following must be true? 5 17 Feb 2011, 17:08
29 If x/|x|, which of the following must be true for all 14 15 Jan 2011, 11:44
Display posts from previous: Sort by


text:
Prisoners and The Lightblub

The scenario:

One day, a drunk warden waltzes into her prison feeling particularly sadistic and decides to put on a little show for herself. She told her guards to gather 100 prisoners into a room so that she could talk to them. When in front of the group of prisoners, she tells them of her plan: All of their prison sentences have been extended indefinitely, but they have a chance to earn their freedom – through her game.

She explained that she arranged for a room to be secured and left with just a single light bulb inside and that nobody but them would be allowed inside. They would then be brought into the room one prisoner per day and allowed to turn the light on or off. It’s guaranteed that nobody else would be given access to the room other than themselves, and that in no way would anyone mess with the light.

They were told that at any time, anyone could come forward and say “I believe all prisoners has been in the room” if they believe it, and if it’s true, all the prisoners go free. If the prisoner says the phrase and it’s not true, they all are killed by firing squad.

Now, you can’t just say the phrase on the 100th day – I mean, you could, but it probably wouldn’t work because the prisoners can be sent in multiple times.

What you know:

1. There are 100 prisoners
2. There is a room with a light bulb that only these prisoners have access to
3. They can really only communicate through this light bulb
4. At any time, any one of them can stop the game, and if all prisoners have been in the room with the light, they go free. If not all prisoners have been in that room, then they all lose the game (or get killed, or the warden steps on their pet bunny or something – something negative happens).

Hints (click to unblur)

1. There’s a non-zero probability (assuming the choice of prisoner is random) that it’s 100,000 years before all prisoners go into that room. So don’t try to find a perfect solution. Just any solution will work.

2. If you haven’t found any solutions, how about putting one prisoner in charge?

Some Solutions

Solution 1

You can put one prisoner in charge and only allow that prisoner to ever turn off the light. Then, whenever anyone else gets in the room, if the light is off and they’ve never turned it on before, turn it on; otherwise, just leave it be. The chosen prisoner ends the game when he or she turns the light off for the 99th time.

That solution is okay, but not great. It gets the job done, but it’ll take forever.

Solution 2

My favorite solution is kinda complicated, but it’s really cool…

So, you pick a number, say, 10. Then, you say make the following rules:

• You assign a notion of “value” to a light-bulb.
• For the first ten days, a light bulb is said to have a value of 1.
• Then every ten days after that, the value doubles, until it gets to 64
• After 64, it goes back to 1.
• Everybody keeps a record in their own respective cells of the value they currently have.
• When a prisoner enters the room, if the light is on, the prisoner turns it off and adds the current day’s value to their own.
• Then, the prisoner writes out the value they have in binary.
• The value of the light bulb progresses to the next day’s value, let’s call it $\lambda$.
• If the prisoner has a “1” in the $\lambda$ place of the binary description of his or her own value, they turn on the light and decrease their own value by $\lambda$.

So, for example, let’s pick 10 as our number of days per value thing. Then if today is the 9th day in the full cycle, then today’s value is 1 (and so is tomorrow’s). So if the light is on when I get in, I turn it off and increment my value. Let’s assume the light is on and I have a value of 20 (or 0010100, in our description). Then I turn off the light and find that I have a value of 21. Since tomorrow’s value is 1, and my binary description is 0010101, I return that point and turn on the light bulb, leaving me with 0010100. If on the other hand, it had been the tenth day and tomorrow’s value were 2, since I’d have a 0 in the 2’s place, I’d keep the point.

The reason I find this solution so interesting is, it really gets to the core of money and value. In this case, the light is only twice as valuable on day 11 as it is on day 10 because we agree to artificially make it so, but as long as we’re doing that, the results are astounding and very real.

Also, this is a completely decentralized solution! Come on, that’s amazing!


text:
# Energy in AC circuits

1. Jun 1, 2012

### p75213

Given that:

E = hν where

E = energy of a photon
h = Planck's constant = 6.626 x 10-34 J·s
ν = frequency

Why is it that the energy (electromagnetic waves) in AC electrical circuits does not include frequency as part of the formula? eg.
$$\begin{array}{l} P = \frac{1}{2}{V_m}{I_m}\varphi \to \omega = \int_0^t {P\,dt} \\ {\rm{Where: }} \\ {\rm{P = average power, }} \\ {V_m} = {\rm{voltage magnitude, }} \\ {I_m}{\rm{ = current magnitude, }} \\ \omega = {\rm{energy, }} \\ \varphi {\rm{ = power factor(}}\cos ({\theta _v} - {\theta _i})) \\ \end{array}$$

The same thing applies to the formula for the energy contained in an inductor:
$$\begin{array}{l} \omega = \frac{1}{2}L{i^2} \\ {\rm{Where:}} \\ L{\rm{ = inductance}} \\ i{\rm{ = current}} \\ \end{array}$$

2. Jun 2, 2012

### Bobbywhy

Electromagnetic waves do not propagate in an AC electrical circuit. Alternating Current flows in an electrical circuit. They are not the same, so they are not described by the same formulas.

3. Jun 2, 2012

### p75213

That's what I thought until I read this: http://amasci.com/miscon/whatis2.html#2
The guy says he is an electrical engineer so I figured he must know what he is talking about.
Seems to make sense as the electrons in AC electricity are simply vibrating inplace. As I understand it a vibrating electron will set up an electromagnetic wave.

Last edited: Jun 2, 2012
4. Jun 2, 2012

### Bob S

Energy (Joules) can be stored in electrical circuits only in capacitors (½CV2) and inductors (½LI2). Power (watts) in electrical circuits is given by V·I (real and reactive). Power (watts per m2) in an electromagnetic wave (including waveguides) is given by the Poynting vector $\overrightarrow{S} = \overrightarrow{E}\times \overrightarrow{H}$ (vector cross product).

5. Jun 2, 2012

### truesearch

p75213...I think your reference is referring to electromagnetic radiation (radio waves usually) from the wires of the circuit.
Whenever AC flows through a wire there is electromagnetic radiation from the wire. It is this radiation that can cause 'interference' in radio reception etc.
This is an energy loss from the circuit and shows that energy must be continuously supplied to maintain oscillation.


text:
# What is anything that has mass and occupies space?

###### Question:

What is anything that has mass and occupies space?

#### Similar Solved Questions

##### Vector A has an x component of -4m and a y component of -8m. a) What...
Vector A has an x component of -4m and a y component of -8m. a) What is the magnitude of A? b) What is the angle of A measured counterclockwise from the x-axis?...
##### A 304 ball bearing carries a radial load of 667 lb and an axial load o...
A 304 ball bearing carries a radial load of 667 lb and an axial load o 125 lb at 300 rpm for 50% of the time, a 600 lb radial load at 500 rpm for the remaining 25% of the time, and a 350 lb radial load at 1,000 rpm for the remaining 25% of the time. The outer ring rotates, and the loads are steady. ...
##### Complete the income statement. Bug-Off Exterminators provides pest control services and sells extermination products manufactured by...
Complete the income statement. Bug-Off Exterminators provides pest control services and sells extermination products manufactured by other companies. Following is the company's unadjusted trial balance as of December 31, 2019. December 31, 2019 Unadjusted Trial Balance $17,000 4,000$ 828 11,70...
##### Hj electron(s) in the e ls orbital, orbital, and the overall bond order is Question 22 (1 point) Consider the CF molecule. In molecular orbital theory, there is a net sigma bond order of A and a...
hj electron(s) in the e ls orbital, orbital, and the overall bond order is Question 22 (1 point) Consider the CF molecule. In molecular orbital theory, there is a net sigma bond order of A and a net pi bond order of Is the molecule paramagnetic or diamagnetic? 10 of 22 questions saved Submit Qulz Ma...
##### Choosing combinations
a carton of 12 transistor batteries contain four that are defective. in how many ways can one choose three so that none of the defective batteries is included?...
##### Only need d 4.12. Typographical errors. Shown below are the number of galleys for a manuscript...
Only need d 4.12. Typographical errors. Shown below are the number of galleys for a manuscript (X) and the total dollar cost of correcting typographical errors (Y) in a random sample of recent orders handled by a firm specializing in technical manuscripts. Since Y involves variable costs only, an an...
##### Esquire Company needs to acquire a molding machine to be used in its manufacturing process. Two...
Esquire Company needs to acquire a molding machine to be used in its manufacturing process. Two types of machines that would be appropriate are presently on the market. The company has determined the following: (FV of $1, PV of$1, FVA of $1, PVA of$1, FVAD of $1 and PVAD of$1) (Use appropriate fa...
##### 1. Assume that it takes 11.5 years for $1,000 to accumulate to$3,000 if you earn...
1. Assume that it takes 11.5 years for $1,000 to accumulate to$3,000 if you earn 10% per year. What will happen to the length of time needed for $1,000 to accumulate to$3,000 if the interest rate increases? A. Stay the same? B. Impossible to determine C. Increase D. Decrease 2. Assume that it take...
##### Assuming that the air follows the adiabatic lapse rate, what should be the temperature on top...
Assuming that the air follows the adiabatic lapse rate, what should be the temperature on top of Mount Everest (8848m) if sea level is at 298K?...
##### The molar solubility of calcium fluoride in a water solution is
The molar solubility of calcium fluoride in a water solution is...
##### 3, 4, 5 Why is the corrosion of car bodies worse in cities that use salt on the streets in the winter than in cit...
3, 4, 5 Why is the corrosion of car bodies worse in cities that use salt on the streets in the winter than in cities that do not use salt? Why are copper straps (rather than iron straps or bent over nails) used to hold household copper wire lines in place? When an iron post is immersed in wate...
##### Choose the BEST reagent for carrying out the following conversion. CO,CH3 COZCHz OH COH СОН Select...
Choose the BEST reagent for carrying out the following conversion. CO,CH3 COZCHz OH COH СОН Select one or more: CrO3, pyridine NaBH4, ethanol LiAlH4, ether H/Pd...
##### Problem 4. Given the input/output system represented by t-1 y(t) = 2 ( x(y - 3)...
Problem 4. Given the input/output system represented by t-1 y(t) = 2 ( x(y - 3) dy where x(t) is the input and y(t) is the output, a) Determine whether the system is linear or non-linear. b) Determine the impulse response h(t, to) of the system by setting x(t)= 8(t–to). c) Determine whether th...
##### Two cars drive on a straight highway. At time t=0, car 1 passes mile marker 0...
Two cars drive on a straight highway. At time t=0, car 1 passes mile marker 0 traveling due east with a speed of 16.0 m/s . At the same time, car 2 is 0.90 km east of mile marker 0 traveling at 30.0 m/s due west. Car 1 is speeding up with an acceleration of magnitude 0.40 m/s2 , and car 2 is slowing...
##### Suppose X and Y have joint distribution function given by: p(x, y) = for (x, y)...
Suppose X and Y have joint distribution function given by: p(x, y) = for (x, y) = (-1,0), (0,1), (1,0). (a) Are X and Y independent? (b) Find the Covariance of X and Y....
##### How do you find all the zeros of P(x)=x^4+6x^2+9?
How do you find all the zeros of P(x)=x^4+6x^2+9?...
##### Visual Basic 2015: Extra 18-1 Use inheritance with the Inventory Maintenance Application Source Code: 1. frmNewItem.vb...
Visual Basic 2015: Extra 18-1 Use inheritance with the Inventory Maintenance Application Source Code: 1. frmNewItem.vb Public Class frmNewItem Public InvItem As InvItem Private Sub frmNewItem_Load(sender As Object, e As EventArgs) Handles MyBase.Load Me.LoadComboBox() End Sub Private Sub LoadComboB...
Section C: Long Question (SK2:15 marks - 1 x 15 marks] C1 - Transactions of Star Company for the month of January 2019 are presented below: 1. On January 1, 2019, the owner invested $75,000 cash in the business. 2. Purchased equipment for$35,000 cash. 3. Purchased supplies on account for \$8,000. 4....


text:
# GL(s,R)

## January 17, 2011

### A multivariable calculus list

In addition to my calculus course this semester, I also get to teach a multivariable calculus course with only six students. I’ll start with the standard list for those interested in that sort of thing.

Spring 2011 Multivariable Calculus Standards List

Let me admit something, here, in between two documents—less likely to read in here—about teaching this course, now for the third time: I’m a fraud. That’s right, I’m a fake, a charlatan, an impostor. I’ve created a counterfeit course and hustle the students with a dash of hocus-pocus and a sprinkle of hoodwinking. It is only through mathematical guile that my misrepresentations, chicanery and flim-flam go unnoticed. In short, and in the passing Christmas spirit, I am a humbug. This is a physics course. It should be taught be someone proficient in physics, someone with honed intuition about the geometry of abstract mathematical notions like div, grad, curl and all that, someone who sees everything as an application of Stokes’ theorem and has strong feelings about whether it should be written Stokes’ theorem or Stokes’s theorem. About the only thing I bring to the table is that I can teach students to remember that:

$\mathrm{curl}(\mathbf{F}) = \nabla \times \mathbf{F}$

and

$\mathrm{div}(\mathbf{F}) = \nabla \cdot \mathbf{F}$

Here is the calendar for the course. After it, I’ll explain a little bit of what I’m trying.

Spring 2011 Multivariable Calculus Calendar

There are several big differences here from how I’ve taught this course in the past. First, I am going to try with all my might to get to Stokes’ theorem before the last week. Part of the way I plan to do this is, similar to my calculus class, to cut out most of the stuff on limits and continuity that I usually get bogged down on in the first couple of weeks—am I the only person who finds interesting the pathological examples that make Clairaut’s theorem necessary? I get to teach an extra hour a week to a subset of the class and that stuff will fit perfectly in there. For the science majors, I’m more interested in helping them figure out how to use this stuff and how to develop intuition. Second, I’m skipping Green’s theorem until the end. Yes, it changes the story I normally tell, one that progresses so nicely up the dimension chart, but the trade-off is that I get more time to show them Stokes’ theorem and more time to focus on the physical interpretation.

Speaking of interpretation, you will notice in the calendar  eleven or so ‘Group Activities’. These are stolen from an excellent guide produced by Dray and Manogue at Oregon State as part of their Bridge Project. To work within their framework, I’ve made another structural change that I’d never considered given how I think about the subject. Immediately after finishing triple integration (which, essentially, finishes the first half of the course), we start with vectors (I never start with vectors as most calculus books do) and then I want to get to line integrals and surface integrals as fast as possible. Normally, I mess around with div and curl before getting to integration of vector fields. Instead, I’m going to push out the Divergence theorem—the theorem I always cover in the last 45 minutes of the course—and use this to motivate the definition of div. Then I’ll push out Stokes’ theorem and use this to help motivate the definition of curl. This ought to give me two solid weeks to explore the physical meaning of these theorems as well as to use them to prove some of the standard cool corollaries (like Green’s theorem).

This class will also be the first of my SBG courses to incorporate a final project. If anyone has good suggestions based on experience about how best to incorporate projects into the SBGrading scheme, I would live to hear them. My current system is quite simplistic. The standards for the course are given a 90% weighting for the overall grade—did I mention that midterms and finals now are simply extended assessments whose grades are treated like an arbitrary quiz, just with a lot more standards tested?—and 10% weighting for the project.

## January 12, 2011

### A Calculus List

Filed under: High Effort/Low Payoff Ideas,Standard Based Grading — Adam Glesser @ 4:19 pm
Tags: ,

One of the advantages of my job is the incredible scheduling. We finished the fall semester the second week of December and my first class of the spring is next Tuesday! The downside is that this gives me way too much time to plot, scheme, doodle, dabble, think, rethink, and overthink. In the end, I usually settle on a plan that is far too ambitious, pedagogically impossible, philosophically suspect, and utterly indefensible. Thus, I bring you my plan for calculus this semester.

I read the wonderful article, Putting Differentials Back Into Calculus, which argues for using differentials in a way closer to their original creation than the way they are employed in modern textbooks.  As a huge fan of Thompson’s Calculus Made Easy, this suggestion didn’t seem half bad. Considering that only a fifth of my students are math majors and that, for the rest, using calculus outside of their physics class is unlikely, why not make things as easy as possible. I’m going to push to teach this same group next fall in calculus II, so the only teacher I can hurt is myself, right? But then I started thinking: the reason the differential approach will work so well with these students is that they will always be using differentiable functions. What reason is there to mention limits and continuity? These are technical issues that won’t help them at all in understanding calculus or how to apply it in their field of inquiry.

Oh dear, so here I am with essentially two months of material (this includes learning to differentiate any elementary function and using this to solve the standard problems). What will I do for the last month and half? I quickly remembered to add Taylor series because I love teaching that in calculus I. Then I added in the obligatory introduction to antiderivatives and integration. I even sprinkled in some partial differentiation at the end so that I could show the students the totally-awesome-implicit-differentiation-trick that would save them five minutes on the final exam. Grr…still two weeks left. These are precisely the two weeks that I usually spend on limits in the beginning. Now I remember why I always do this. It perfectly fills in the semester calendar. And then it hits me.

Any subject can be made repulsive by presenting it bristling with difficulties.
—Silvanus P. Thompson

Limits sure confuse the heck out of students. Why in the world are we leading calculus off with limits, especially to non-math majors? For the purpose of rigor?

You don’t forbid the use of a watch to every person who does not know how to make one? You don’t object to the musician playing on a violin that he has not himself constructed. You don’t teach the rules of syntax to children until they have already become fluent in the use of speech. It would be equally absurd to require rigid demonstrations to be expounded to beginners in the calculus.
—Silvanus P. Thompson

So I decide I just won’t do it.  No limits for us. We will just do some extra exploratory work. There is a great article on math in medicine we could read together. Okay, time for sleep.

But sleep does not come.

Toss.

Turn.

Toss.

Turn.

All right. All right. I’m up.

Why can’t the limits just die? Why do I feel the compulsion to put them back in? They’re like the tell-tale heart beating under my floor. What will become of my math majors if they don’t see limits? No, I can’t do that to them. What a cruel joke to play: send them to real analysis without having used limits. Back in they go. Of course, those biology majors are going to be completely turned off and once you lose them, they’re gone for good. Argh, out they go. On the other hand, if I get audited by the department, they are sure going to ask questions. With my review coming up, I can’t afford that kind of chatter. Put them back in…

…but later. Huh? Put them back in, but later. Yes, of course. Later. The course description says I need to cover limits, but it doesn’t say when! What if we introduced everything in a reasonable way and, only after the students know what is going on and why any of this is important, then showed them those funky limit do-hickies? Hmm. Interesting. And that is my explanation for the following calendar and skills list:

View this document on Scribd
View this document on Scribd

Create a free website or blog at WordPress.com.


text:
## The ineffable tree property II

Speaker:
Spencer Unger
Institution:
Carnegie Mellon University
Time:
Wed, 02/15/2012 - 4:00pm
Location:
RH 306

In this series of two talks I will give an introduction to some of my recent research on the ineffable tree property. The ineffable tree property is a two cardinal combinatorial principle which can consistently hold at small cardinals. My recent work has been on generalizing results about the classical tree property to the setting of the ineffable tree property. The main theorem that I will work towards in these talks generalizes a theorem of Cummings and Foreman. From omega supercompact cardinals, Cummings and Foreman constructed a model where the tree property holds at all of the $\aleph_n$ with $1 < n < \omega$. I recently proved that in their model the $(\aleph_n,\lambda)$ ineffable tree property holds for all $n$ with $1 < n < \omega$ and $\lambda \geq \aleph_n$.


text:
How do you define a variable and write an expression for each phrase: a number minus the difference of the number and four?

Jul 17, 2016

$x - \left(x - 4\right)$

Explanation:

Let's call the "number" referred to as $x$.

The word DIFFERENCE is always linked with AND.

The DIFFERENCE between/of 10 AND 8 is 2. ($10 - 8 = 2$)

"A number minus ????" means $x$ - ????

"(A number minus) the (difference of the number and four)"

$\text{ "x -" } \left(x - 4\right)$

$x - \left(x - 4\right)$


text:
# Chapter 10 - Radical Expressions and Equations - Mid-Chapter Quiz: 23

$8\sqrt5$

#### Work Step by Step

$5\sqrt5+3\sqrt5\longrightarrow$ distributive property =$\sqrt5(5+3)\longrightarrow$ add =$8\sqrt5$

After you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.


text:
# sklearn.decomposition.KernelPCA¶

class sklearn.decomposition.KernelPCA(n_components=None, *, kernel='linear', gamma=None, degree=3, coef0=1, kernel_params=None, alpha=1.0, fit_inverse_transform=False, eigen_solver='auto', tol=0, max_iter=None, iterated_power='auto', remove_zero_eig=False, random_state=None, copy_X=True, n_jobs=None)[source]

Kernel Principal component analysis (KPCA).

Non-linear dimensionality reduction through the use of kernels (see Pairwise metrics, Affinities and Kernels).

It uses the scipy.linalg.eigh LAPACK implementation of the full SVD or the scipy.sparse.linalg.eigsh ARPACK implementation of the truncated SVD, depending on the shape of the input data and the number of components to extract. It can also use a randomized truncated SVD by the method of Halko et al. 2009, see eigen_solver.

Read more in the User Guide.

Parameters
n_componentsint, default=None

Number of components. If None, all non-zero components are kept.

kernel{‘linear’, ‘poly’, ‘rbf’, ‘sigmoid’, ‘cosine’, ‘precomputed’}, default=’linear’

Kernel used for PCA.

gammafloat, default=None

Kernel coefficient for rbf, poly and sigmoid kernels. Ignored by other kernels. If gamma is None, then it is set to 1/n_features.

degreeint, default=3

Degree for poly kernels. Ignored by other kernels.

coef0float, default=1

Independent term in poly and sigmoid kernels. Ignored by other kernels.

kernel_paramsdict, default=None

Parameters (keyword arguments) and values for kernel passed as callable object. Ignored by other kernels.

alphafloat, default=1.0

Hyperparameter of the ridge regression that learns the inverse transform (when fit_inverse_transform=True).

fit_inverse_transformbool, default=False

Learn the inverse transform for non-precomputed kernels. (i.e. learn to find the pre-image of a point)

eigen_solver{‘auto’, ‘dense’, ‘arpack’, ‘randomized’}, default=’auto’

Select eigensolver to use. If n_components is much less than the number of training samples, randomized (or arpack to a smaller extend) may be more efficient than the dense eigensolver. Randomized SVD is performed according to the method of Halko et al.

auto :

the solver is selected by a default policy based on n_samples (the number of training samples) and n_components: if the number of components to extract is less than 10 (strict) and the number of samples is more than 200 (strict), the ‘arpack’ method is enabled. Otherwise the exact full eigenvalue decomposition is computed and optionally truncated afterwards (‘dense’ method).

dense :

run exact full eigenvalue decomposition calling the standard LAPACK solver via scipy.linalg.eigh, and select the components by postprocessing

arpack :

run SVD truncated to n_components calling ARPACK solver using scipy.sparse.linalg.eigsh. It requires strictly 0 < n_components < n_samples

randomized :

run randomized SVD by the method of Halko et al. The current implementation selects eigenvalues based on their module; therefore using this method can lead to unexpected results if the kernel is not positive semi-definite.

Changed in version 1.0: 'randomized' was added.

tolfloat, default=0

Convergence tolerance for arpack. If 0, optimal value will be chosen by arpack.

max_iterint, default=None

Maximum number of iterations for arpack. If None, optimal value will be chosen by arpack.

iterated_powerint >= 0, or ‘auto’, default=’auto’

Number of iterations for the power method computed by svd_solver == ‘randomized’. When ‘auto’, it is set to 7 when n_components < 0.1 * min(X.shape), other it is set to 4.

New in version 1.0.

remove_zero_eigbool, default=False

If True, then all components with zero eigenvalues are removed, so that the number of components in the output may be < n_components (and sometimes even zero due to numerical instability). When n_components is None, this parameter is ignored and components with zero eigenvalues are removed regardless.

random_stateint, RandomState instance or None, default=None

Used when eigen_solver == ‘arpack’ or ‘randomized’. Pass an int for reproducible results across multiple function calls. See Glossary.

New in version 0.18.

copy_Xbool, default=True

If True, input X is copied and stored by the model in the X_fit_ attribute. If no further changes will be done to X, setting copy_X=False saves memory by storing a reference.

New in version 0.18.

n_jobsint, default=None

The number of parallel jobs to run. None means 1 unless in a joblib.parallel_backend context. -1 means using all processors. See Glossary for more details.

New in version 0.18.

Attributes
lambdas_ndarray of shape (n_components,)

Eigenvalues of the centered kernel matrix in decreasing order. If n_components and remove_zero_eig are not set, then all values are stored.

alphas_ndarray of shape (n_samples, n_components)

Eigenvectors of the centered kernel matrix. If n_components and remove_zero_eig are not set, then all components are stored.

dual_coef_ndarray of shape (n_samples, n_features)

Inverse transform matrix. Only available when fit_inverse_transform is True.

X_transformed_fit_ndarray of shape (n_samples, n_components)

Projection of the fitted data on the kernel principal components. Only available when fit_inverse_transform is True.

X_fit_ndarray of shape (n_samples, n_features)

The data used to fit the model. If copy_X=False, then X_fit_ is a reference. This attribute is used for the calls to transform.

n_features_in_int

Number of features seen during fit.

New in version 0.24.

References

Kernel PCA was introduced in:

Bernhard Schoelkopf, Alexander J. Smola, and Klaus-Robert Mueller. 1999. Kernel principal component analysis. In Advances in kernel methods, MIT Press, Cambridge, MA, USA 327-352.

For eigen_solver == ‘arpack’, refer to scipy.sparse.linalg.eigsh.

For eigen_solver == ‘randomized’, see:

Finding structure with randomness: Stochastic algorithms for constructing approximate matrix decompositions Halko, et al., 2009 (arXiv:909) A randomized algorithm for the decomposition of matrices Per-Gunnar Martinsson, Vladimir Rokhlin and Mark Tygert

Examples

>>> from sklearn.datasets import load_digits
>>> from sklearn.decomposition import KernelPCA
>>> transformer = KernelPCA(n_components=7, kernel='linear')
>>> X_transformed = transformer.fit_transform(X)
>>> X_transformed.shape
(1797, 7)

Methods

 fit(X[, y]) Fit the model from data in X. fit_transform(X[, y]) Fit the model from data in X and transform X. get_params([deep]) Get parameters for this estimator. Transform X back to original space. set_params(**params) Set the parameters of this estimator. Transform X.
fit(X, y=None)[source]

Fit the model from data in X.

Parameters
X{array-like, sparse matrix} of shape (n_samples, n_features)

Training vector, where n_samples in the number of samples and n_features is the number of features.

Returns
selfobject

Returns the instance itself.

fit_transform(X, y=None, **params)[source]

Fit the model from data in X and transform X.

Parameters
X{array-like, sparse matrix} of shape (n_samples, n_features)

Training vector, where n_samples in the number of samples and n_features is the number of features.

Returns
X_newndarray of shape (n_samples, n_components)
get_params(deep=True)[source]

Get parameters for this estimator.

Parameters
deepbool, default=True

If True, will return the parameters for this estimator and contained subobjects that are estimators.

Returns
paramsdict

Parameter names mapped to their values.

inverse_transform(X)[source]

Transform X back to original space.

inverse_transform approximates the inverse transformation using a learned pre-image. The pre-image is learned by kernel ridge regression of the original data on their low-dimensional representation vectors.

Note

When users want to compute inverse transformation for ‘linear’ kernel, it is recommended that they use PCA instead. Unlike PCA, KernelPCA’s inverse_transform does not reconstruct the mean of data when ‘linear’ kernel is used due to the use of centered kernel.

Parameters
X{array-like, sparse matrix} of shape (n_samples, n_components)
Returns
X_newndarray of shape (n_samples, n_features)

References

“Learning to Find Pre-Images”, G BakIr et al, 2004.

set_params(**params)[source]

Set the parameters of this estimator.

The method works on simple estimators as well as on nested objects (such as Pipeline). The latter have parameters of the form <component>__<parameter> so that it’s possible to update each component of a nested object.

Parameters
**paramsdict

Estimator parameters.

Returns
selfestimator instance

Estimator instance.

transform(X)[source]

Transform X.

Parameters
X{array-like, sparse matrix} of shape (n_samples, n_features)
Returns
X_newndarray of shape (n_samples, n_components)