<!-- Generated by pkgdown: do not edit by hand -->
<!DOCTYPE html>
<html lang="en">
  <head>
  <meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">

<title>Class comparison between two nominal rasters — class.comparison • spatialEco</title>


<!-- jquery -->
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.4.1/jquery.min.js" integrity="sha256-CSXorXvZcTkaix6Yvo6HppcZGetbYMGWSFlBw8HfCJo=" crossorigin="anonymous"></script>
<!-- Bootstrap -->

<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.4.1/css/bootstrap.min.css" integrity="sha256-bZLfwXAP04zRMK2BjiO8iu9pf4FbLqX6zitd+tIvLhE=" crossorigin="anonymous" />

<script src="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.4.1/js/bootstrap.min.js" integrity="sha256-nuL8/2cJ5NDSSwnKD8VqreErSWHtnEP9E7AySL+1ev4=" crossorigin="anonymous"></script>

<!-- bootstrap-toc -->
<link rel="stylesheet" href="../bootstrap-toc.css">
<script src="../bootstrap-toc.js"></script>

<!-- Font Awesome icons -->
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/5.12.1/css/all.min.css" integrity="sha256-mmgLkCYLUQbXn0B1SRqzHar6dCnv9oZFPEC1g1cwlkk=" crossorigin="anonymous" />
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/5.12.1/css/v4-shims.min.css" integrity="sha256-wZjR52fzng1pJHwx4aV2AO3yyTOXrcDW7jBpJtTwVxw=" crossorigin="anonymous" />

<!-- clipboard.js -->
<script src="https://cdnjs.cloudflare.com/ajax/libs/clipboard.js/2.0.6/clipboard.min.js" integrity="sha256-inc5kl9MA1hkeYUt+EC3BhlIgyp/2jDIyBLS6k3UxPI=" crossorigin="anonymous"></script>

<!-- headroom.js -->
<script src="https://cdnjs.cloudflare.com/ajax/libs/headroom/0.11.0/headroom.min.js" integrity="sha256-AsUX4SJE1+yuDu5+mAVzJbuYNPHj/WroHuZ8Ir/CkE0=" crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/headroom/0.11.0/jQuery.headroom.min.js" integrity="sha256-ZX/yNShbjqsohH1k95liqY9Gd8uOiE1S4vZc+9KQ1K4=" crossorigin="anonymous"></script>

<!-- pkgdown -->
<link href="../pkgdown.css" rel="stylesheet">
<script src="../pkgdown.js"></script>




<meta property="og:title" content="Class comparison between two nominal rasters — class.comparison" />
<meta property="og:description" content="Compares two categorical rasters using Cohen's Kappa (d) 
             or paired t-test statistic(s)" />




<!-- mathjax -->
<script src="https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.5/MathJax.js" integrity="sha256-nvJJv9wWKEm88qvoQl9ekL2J+k/RWIsaSScxxlsrv8k=" crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.5/config/TeX-AMS-MML_HTMLorMML.js" integrity="sha256-84DKXVJXs0/F8OTMzX4UR909+jtl4G7SPypPavF+GfA=" crossorigin="anonymous"></script>

<!--[if lt IE 9]>
<script src="https://oss.maxcdn.com/html5shiv/3.7.3/html5shiv.min.js"></script>
<script src="https://oss.maxcdn.com/respond/1.4.2/respond.min.js"></script>
<![endif]-->



  </head>

  <body data-spy="scroll" data-target="#toc">
    <div class="container template-reference-topic">
      <header>
      <div class="navbar navbar-default navbar-fixed-top" role="navigation">
  <div class="container">
    <div class="navbar-header">
      <button type="button" class="navbar-toggle collapsed" data-toggle="collapse" data-target="#navbar" aria-expanded="false">
        <span class="sr-only">Toggle navigation</span>
        <span class="icon-bar"></span>
        <span class="icon-bar"></span>
        <span class="icon-bar"></span>
      </button>
      <span class="navbar-brand">
        <a class="navbar-link" href="../index.html">spatialEco</a>
        <span class="version label label-default" data-toggle="tooltip" data-placement="bottom" title="Released version">1.3-7</span>
      </span>
    </div>

    <div id="navbar" class="navbar-collapse collapse">
      <ul class="nav navbar-nav">
        <li>
  <a href="../index.html">
    <span class="fas fa-home fa-lg"></span>
     
  </a>
</li>
<li>
  <a href="../reference/index.html">Reference</a>
</li>
      </ul>
      <ul class="nav navbar-nav navbar-right">
        <li>
  <a href="https://github.com/jeffreyevans/spatialEco/">
    <span class="fab fa-github fa-lg"></span>
     
  </a>
</li>
      </ul>
      
    </div><!--/.nav-collapse -->
  </div><!--/.container -->
</div><!--/.navbar -->

      

      </header>

<div class="row">
  <div class="col-md-9 contents">
    <div class="page-header">
    <h1>Class comparison between two nominal rasters</h1>
    <small class="dont-index">Source: <a href='https://github.com/jeffreyevans/spatialEco/blob/master/R/class.comparison.R'><code>R/class.comparison.R</code></a></small>
    <div class="hidden name"><code>class.comparison.Rd</code></div>
    </div>

    <div class="ref-description">
    <p>Compares two categorical rasters using Cohen's Kappa (d) 
             or paired t-test statistic(s)</p>
    </div>

    <pre class="usage"><span class='fu'>class.comparison</span><span class='op'>(</span>
  <span class='va'>x</span>,
  <span class='va'>y</span>,
  x.idx <span class='op'>=</span> <span class='fl'>1</span>,
  y.idx <span class='op'>=</span> <span class='fl'>1</span>,
  d <span class='op'>=</span> <span class='st'>"AUTO"</span>,
  stat <span class='op'>=</span> <span class='st'>"kappa"</span>,
  sub.sample <span class='op'>=</span> <span class='cn'>FALSE</span>,
  type <span class='op'>=</span> <span class='st'>"hexagon"</span>,
  p <span class='op'>=</span> <span class='fl'>0.1</span>,
  size <span class='op'>=</span> <span class='cn'>NULL</span>
<span class='op'>)</span></pre>

    <h2 class="hasAnchor" id="arguments"><a class="anchor" href="#arguments"></a>Arguments</h2>
    <table class="ref-arguments">
    <colgroup><col class="name" /><col class="desc" /></colgroup>
    <tr>
      <th>x</th>
      <td><p>First raster for comparison, SpatialPixelsDataFrame or 
SpatialGridDataFrame object</p></td>
    </tr>
    <tr>
      <th>y</th>
      <td><p>Second raster for comparison, SpatialPixelsDataFrame or 
SpatialGridDataFrame object</p></td>
    </tr>
    <tr>
      <th>x.idx</th>
      <td><p>Index for the column in the x raster object</p></td>
    </tr>
    <tr>
      <th>y.idx</th>
      <td><p>Index for the column in the y raster object</p></td>
    </tr>
    <tr>
      <th>d</th>
      <td><p>Distance for finding neighbors, the default "AUTO" will derive 
a distance</p></td>
    </tr>
    <tr>
      <th>stat</th>
      <td><p>Statistic to use in comparison ("kappa", "t.test", "both")</p></td>
    </tr>
    <tr>
      <th>sub.sample</th>
      <td><p>Should a subsampling approach be employed (FALSE/TRUE)</p></td>
    </tr>
    <tr>
      <th>type</th>
      <td><p>If sub.sample = TRUE, what type of sample ("random"
or "hexagon")</p></td>
    </tr>
    <tr>
      <th>p</th>
      <td><p>If sub.sample = TRUE, what proportion of population 
should be sampled</p></td>
    </tr>
    <tr>
      <th>size</th>
      <td><p>If sub.sample = TRUE, alternate to proportion of population (p), 
using fixed sample size</p></td>
    </tr>
    </table>

    <h2 class="hasAnchor" id="value"><a class="anchor" href="#value"></a>Value</h2>

    <p>A SpatialPixelsDataFrame or SpatialPointsDataFrame with the 
following attributes:</p><ul>
<li><p>x        x variable used to derive Kappa (d)</p></li>
<li><p>y        y variable used to derive Kappa (d)</p></li>
<li><p>kappa    Kappa (d) statistic</p></li>
<li><p>t.test   Paired t.test statistic  (if stat = "t.test" or "both")</p></li>
<li><p>p.value  p-value of the paired t.test statistic (if stat = "t.test" 
                 or "both")</p></li>
</ul>

    <h2 class="hasAnchor" id="note"><a class="anchor" href="#note"></a>Note</h2>

    <p>This function provides a Cohen's Kappa or paired t-test to compare two 
classified maps. Point based subsampling is provided for computation 
tractability.  The hexagon sampling is recommended as it it good at 
capturing spatial process that includes nonstationarity and anisotropy.</p>
    <h2 class="hasAnchor" id="references"><a class="anchor" href="#references"></a>References</h2>

    <p>Cohen, J. (1960). A coefficient of agreement for nominal scales. Educational 
and Psychological Measurement, 20:37-46</p>
    <h2 class="hasAnchor" id="author"><a class="anchor" href="#author"></a>Author</h2>

    <p>Jeffrey S. Evans  &lt;jeffrey_evans@tnc.org&gt;</p>

    <h2 class="hasAnchor" id="examples"><a class="anchor" href="#examples"></a>Examples</h2>
    <pre class="examples"><div class='input'><span class='co'># \donttest{</span>
 <span class='kw'><a href='https://rdrr.io/r/base/library.html'>library</a></span><span class='op'>(</span><span class='va'><a href='https://github.com/edzer/sp/'>sp</a></span><span class='op'>)</span>                                            
 <span class='kw'><a href='https://rdrr.io/r/base/library.html'>library</a></span><span class='op'>(</span><span class='va'><a href='https://rspatial.org/raster'>raster</a></span><span class='op'>)</span>
           
 <span class='fu'><a href='https://rdrr.io/r/utils/data.html'>data</a></span><span class='op'>(</span><span class='va'>meuse.grid</span><span class='op'>)</span>
 <span class='va'>r1</span> <span class='op'>&lt;-</span> <span class='fu'>sp</span><span class='fu'>::</span><span class='fu'><a href='https://rdrr.io/pkg/sp/man/SpatialGridDataFrame.html'>SpatialPixelsDataFrame</a></span><span class='op'>(</span>points <span class='op'>=</span> <span class='va'>meuse.grid</span><span class='op'>[</span><span class='fu'><a href='https://rdrr.io/r/base/c.html'>c</a></span><span class='op'>(</span><span class='st'>"x"</span>, <span class='st'>"y"</span><span class='op'>)</span><span class='op'>]</span>, 
                                  data <span class='op'>=</span> <span class='va'>meuse.grid</span><span class='op'>)</span>
   <span class='va'>r1</span><span class='op'>@</span><span class='va'>data</span><span class='op'>$</span><span class='va'>class1</span> <span class='op'>&lt;-</span> <span class='fu'><a href='https://rdrr.io/r/base/Round.html'>round</a></span><span class='op'>(</span><span class='fu'><a href='https://rdrr.io/r/stats/Uniform.html'>runif</a></span><span class='op'>(</span><span class='fu'><a href='https://rdrr.io/pkg/raster/man/ncell.html'>nrow</a></span><span class='op'>(</span><span class='va'>r1</span><span class='op'>)</span>, <span class='fl'>1</span>,<span class='fl'>5</span><span class='op'>)</span>,<span class='fl'>0</span><span class='op'>)</span>
 <span class='va'>r2</span> <span class='op'>&lt;-</span> <span class='fu'>sp</span><span class='fu'>::</span><span class='fu'><a href='https://rdrr.io/pkg/sp/man/SpatialGridDataFrame.html'>SpatialPixelsDataFrame</a></span><span class='op'>(</span>points <span class='op'>=</span> <span class='va'>meuse.grid</span><span class='op'>[</span><span class='fu'><a href='https://rdrr.io/r/base/c.html'>c</a></span><span class='op'>(</span><span class='st'>"x"</span>, <span class='st'>"y"</span><span class='op'>)</span><span class='op'>]</span>, 
                                  data <span class='op'>=</span> <span class='va'>meuse.grid</span><span class='op'>)</span> 
<span class='va'>r2</span><span class='op'>@</span><span class='va'>data</span><span class='op'>$</span><span class='va'>class2</span> <span class='op'>&lt;-</span> <span class='fu'><a href='https://rdrr.io/r/base/Round.html'>round</a></span><span class='op'>(</span><span class='fu'><a href='https://rdrr.io/r/stats/Uniform.html'>runif</a></span><span class='op'>(</span><span class='fu'><a href='https://rdrr.io/pkg/raster/man/ncell.html'>nrow</a></span><span class='op'>(</span><span class='va'>r2</span><span class='op'>)</span>, <span class='fl'>1</span>,<span class='fl'>5</span><span class='op'>)</span>,<span class='fl'>0</span><span class='op'>)</span>

 <span class='va'>d</span> <span class='op'>&lt;-</span> <span class='fu'>class.comparison</span><span class='op'>(</span><span class='va'>r1</span>, <span class='va'>r2</span>, x.idx <span class='op'>=</span> <span class='fl'>8</span>, y.idx <span class='op'>=</span> <span class='fl'>8</span>, stat<span class='op'>=</span><span class='st'>"both"</span><span class='op'>)</span>
 <span class='va'>opar</span> <span class='op'>&lt;-</span> <span class='fu'><a href='https://rdrr.io/r/graphics/par.html'>par</a></span><span class='op'>(</span>no.readonly<span class='op'>=</span><span class='cn'>TRUE</span><span class='op'>)</span>
   <span class='fu'><a href='https://rdrr.io/r/graphics/par.html'>par</a></span><span class='op'>(</span>mfrow<span class='op'>=</span><span class='fu'><a href='https://rdrr.io/r/base/c.html'>c</a></span><span class='op'>(</span><span class='fl'>2</span>,<span class='fl'>2</span><span class='op'>)</span><span class='op'>)</span>
     <span class='fu'><a href='https://rdrr.io/pkg/raster/man/plot.html'>plot</a></span><span class='op'>(</span><span class='fu'><a href='https://rdrr.io/pkg/raster/man/raster.html'>raster</a></span><span class='op'>(</span><span class='va'>d</span>, layer<span class='op'>=</span><span class='fl'>3</span><span class='op'>)</span>, main<span class='op'>=</span><span class='st'>"Kappa"</span><span class='op'>)</span>
    <span class='fu'><a href='https://rdrr.io/pkg/raster/man/plot.html'>plot</a></span><span class='op'>(</span><span class='fu'><a href='https://rdrr.io/pkg/raster/man/raster.html'>raster</a></span><span class='op'>(</span><span class='va'>d</span>, layer<span class='op'>=</span><span class='fl'>4</span><span class='op'>)</span>, main<span class='op'>=</span><span class='st'>"t.test"</span><span class='op'>)</span>
    <span class='fu'><a href='https://rdrr.io/pkg/raster/man/plot.html'>plot</a></span><span class='op'>(</span><span class='fu'><a href='https://rdrr.io/pkg/raster/man/raster.html'>raster</a></span><span class='op'>(</span><span class='va'>d</span>, layer<span class='op'>=</span><span class='fl'>5</span><span class='op'>)</span>, main<span class='op'>=</span><span class='st'>"t.test p-value"</span><span class='op'>)</span>
 <span class='fu'><a href='https://rdrr.io/r/graphics/par.html'>par</a></span><span class='op'>(</span><span class='va'>opar</span><span class='op'>)</span>
</div><div class='img'><img src='class.comparison-1.png' alt='' width='700' height='433' /></div><div class='input'> <span class='co'># Hexagonal sampling    </span>
 <span class='va'>d.hex</span> <span class='op'>&lt;-</span> <span class='fu'>class.comparison</span><span class='op'>(</span><span class='va'>r1</span>, <span class='va'>r2</span>, x.idx <span class='op'>=</span> <span class='fl'>8</span>, y.idx <span class='op'>=</span> <span class='fl'>8</span>, stat <span class='op'>=</span> <span class='st'>"both"</span>,
                           sub.sample <span class='op'>=</span> <span class='cn'>TRUE</span>, d <span class='op'>=</span> <span class='fl'>500</span>, size <span class='op'>=</span> <span class='fl'>1000</span><span class='op'>)</span>
   <span class='fu'>sp</span><span class='fu'>::</span><span class='fu'><a href='https://rdrr.io/pkg/sp/man/bubble.html'>bubble</a></span><span class='op'>(</span><span class='va'>d.hex</span>, <span class='st'>"kappa"</span><span class='op'>)</span>
</div><div class='img'><img src='class.comparison-2.png' alt='' width='700' height='433' /></div><div class='input'>    <span class='va'>d.hex</span> <span class='op'>&lt;-</span> <span class='fu'><a href='sp.na.omit.html'>sp.na.omit</a></span><span class='op'>(</span><span class='va'>d.hex</span>, col.name <span class='op'>=</span> <span class='st'>"t.test"</span><span class='op'>)</span>
  <span class='fu'>sp</span><span class='fu'>::</span><span class='fu'><a href='https://rdrr.io/pkg/sp/man/bubble.html'>bubble</a></span><span class='op'>(</span><span class='va'>d.hex</span>, <span class='st'>"t.test"</span><span class='op'>)</span>
</div><div class='img'><img src='class.comparison-3.png' alt='' width='700' height='433' /></div><div class='input'><span class='co'># }</span>

</div></pre>
  </div>
  <div class="col-md-3 hidden-xs hidden-sm" id="pkgdown-sidebar">
    <nav id="toc" data-toggle="toc" class="sticky-top">
      <h2 data-toc-skip>Contents</h2>
    </nav>
  </div>
</div>


      <footer>
      <div class="copyright">
  <p>Developed by Jeffrey S. Evans.</p>
</div>

<div class="pkgdown">
  <p>Site built with <a href="https://pkgdown.r-lib.org/">pkgdown</a> 1.6.1.</p>
</div>

      </footer>
   </div>

  


  </body>
</html>


