<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>Recognizing hand-written digits — scikits.learn v0.6.0 documentation</title> <link rel="stylesheet" href="../_static/nature.css" type="text/css" /> <link rel="stylesheet" href="../_static/pygments.css" type="text/css" /> <script type="text/javascript"> var DOCUMENTATION_OPTIONS = { URL_ROOT: '../', VERSION: '0.6.0', COLLAPSE_INDEX: false, FILE_SUFFIX: '.html', HAS_SOURCE: true }; </script> <script type="text/javascript" src="../_static/jquery.js"></script> <script type="text/javascript" src="../_static/underscore.js"></script> <script type="text/javascript" src="../_static/doctools.js"></script> <link rel="shortcut icon" href="../_static/favicon.ico"/> <link rel="author" title="About these documents" href="../about.html" /> <link rel="top" title="scikits.learn v0.6.0 documentation" href="../index.html" /> <link rel="up" title="Examples" href="index.html" /> <link rel="next" title="Univariate Feature Selection" href="plot_feature_selection.html" /> <link rel="prev" title="Ledoit-Wolf vs Covariance simple estimation" href="plot_covariance_estimation.html" /> </head> <body> <div class="header-wrapper"> <div class="header"> <p class="logo"><a href="../index.html"> <img src="../_static/scikit-learn-logo-small.png" alt="Logo"/> </a> </p><div class="navbar"> <ul> <li><a href="../install.html">Download</a></li> <li><a href="../support.html">Support</a></li> <li><a href="../user_guide.html">User Guide</a></li> <li><a href="index.html">Examples</a></li> <li><a href="../developers/index.html">Development</a></li> </ul> <div class="search_form"> <div id="cse" style="width: 100%;"></div> <script src="http://www.google.com/jsapi" type="text/javascript"></script> <script type="text/javascript"> google.load('search', '1', {language : 'en'}); google.setOnLoadCallback(function() { var customSearchControl = new google.search.CustomSearchControl('016639176250731907682:tjtqbvtvij0'); customSearchControl.setResultSetSize(google.search.Search.FILTERED_CSE_RESULTSET); var options = new google.search.DrawOptions(); options.setAutoComplete(true); customSearchControl.draw('cse', options); }, true); </script> </div> </div> <!-- end navbar --></div> </div> <div class="content-wrapper"> <!-- <div id="blue_tile"></div> --> <div class="sphinxsidebar"> <div class="rel"> <a href="plot_covariance_estimation.html" title="Ledoit-Wolf vs Covariance simple estimation" accesskey="P">previous</a> | <a href="plot_feature_selection.html" title="Univariate Feature Selection" accesskey="N">next</a> | <a href="../genindex.html" title="General Index" accesskey="I">index</a> </div> <h3>Contents</h3> <ul> <li><a class="reference internal" href="#">Recognizing hand-written digits</a></li> </ul> </div> <div class="content"> <div class="documentwrapper"> <div class="bodywrapper"> <div class="body"> <div class="section" id="recognizing-hand-written-digits"> <span id="example-plot-digits-classification-py"></span><h1>Recognizing hand-written digits<a class="headerlink" href="#recognizing-hand-written-digits" title="Permalink to this headline">ΒΆ</a></h1> <p>An example showing how the scikit-learn can be used to recognize images of hand-written digits.</p> <img alt="auto_examples/images/plot_digits_classification.png" class="align-center" src="auto_examples/images/plot_digits_classification.png" /> <p><strong>Python source code:</strong> <a class="reference download internal" href="../_downloads/plot_digits_classification.py"><tt class="xref download docutils literal"><span class="pre">plot_digits_classification.py</span></tt></a></p> <div class="highlight-python"><div class="highlight"><pre><span class="k">print</span> <span class="n">__doc__</span> <span class="c"># Author: Gael Varoquaux <gael dot varoquaux at normalesup dot org></span> <span class="c"># License: Simplified BSD</span> <span class="c"># Standard scientific Python imports</span> <span class="kn">import</span> <span class="nn">pylab</span> <span class="kn">as</span> <span class="nn">pl</span> <span class="c"># The digits dataset</span> <span class="kn">from</span> <span class="nn">scikits.learn</span> <span class="kn">import</span> <span class="n">datasets</span> <span class="n">digits</span> <span class="o">=</span> <span class="n">datasets</span><span class="o">.</span><span class="n">load_digits</span><span class="p">()</span> <span class="c"># The data that we are interesting in is made of 8x8 images of digits,</span> <span class="c"># let's have a look at the first 3 images. We know which digit they</span> <span class="c"># represent: it is given in the 'target' of the dataset.</span> <span class="k">for</span> <span class="n">index</span><span class="p">,</span> <span class="p">(</span><span class="n">image</span><span class="p">,</span> <span class="n">label</span><span class="p">)</span> <span class="ow">in</span> <span class="nb">enumerate</span><span class="p">(</span><span class="nb">zip</span><span class="p">(</span><span class="n">digits</span><span class="o">.</span><span class="n">images</span><span class="p">,</span> <span class="n">digits</span><span class="o">.</span><span class="n">target</span><span class="p">)[:</span><span class="mi">4</span><span class="p">]):</span> <span class="n">pl</span><span class="o">.</span><span class="n">subplot</span><span class="p">(</span><span class="mi">2</span><span class="p">,</span> <span class="mi">4</span><span class="p">,</span> <span class="n">index</span><span class="o">+</span><span class="mi">1</span><span class="p">)</span> <span class="n">pl</span><span class="o">.</span><span class="n">imshow</span><span class="p">(</span><span class="n">image</span><span class="p">,</span> <span class="n">cmap</span><span class="o">=</span><span class="n">pl</span><span class="o">.</span><span class="n">cm</span><span class="o">.</span><span class="n">gray_r</span><span class="p">)</span> <span class="n">pl</span><span class="o">.</span><span class="n">title</span><span class="p">(</span><span class="s">'Training: </span><span class="si">%i</span><span class="s">'</span> <span class="o">%</span> <span class="n">label</span><span class="p">)</span> <span class="c"># To apply an classifier on this data, we need to flatten the image, to</span> <span class="c"># turn the data in a (samples, feature) matrix:</span> <span class="n">n_samples</span> <span class="o">=</span> <span class="nb">len</span><span class="p">(</span><span class="n">digits</span><span class="o">.</span><span class="n">images</span><span class="p">)</span> <span class="n">data</span> <span class="o">=</span> <span class="n">digits</span><span class="o">.</span><span class="n">images</span><span class="o">.</span><span class="n">reshape</span><span class="p">((</span><span class="n">n_samples</span><span class="p">,</span> <span class="o">-</span><span class="mi">1</span><span class="p">))</span> <span class="c"># Import a classifier:</span> <span class="kn">from</span> <span class="nn">scikits.learn</span> <span class="kn">import</span> <span class="n">svm</span> <span class="kn">from</span> <span class="nn">scikits.learn.metrics</span> <span class="kn">import</span> <span class="n">classification_report</span> <span class="kn">from</span> <span class="nn">scikits.learn.metrics</span> <span class="kn">import</span> <span class="n">confusion_matrix</span> <span class="n">classifier</span> <span class="o">=</span> <span class="n">svm</span><span class="o">.</span><span class="n">SVC</span><span class="p">()</span> <span class="c"># We learn the digits on the first half of the digits</span> <span class="n">classifier</span><span class="o">.</span><span class="n">fit</span><span class="p">(</span><span class="n">data</span><span class="p">[:</span><span class="n">n_samples</span><span class="o">/</span><span class="mi">2</span><span class="p">],</span> <span class="n">digits</span><span class="o">.</span><span class="n">target</span><span class="p">[:</span><span class="n">n_samples</span><span class="o">/</span><span class="mi">2</span><span class="p">])</span> <span class="c"># Now predict the value of the digit on the second half:</span> <span class="n">expected</span> <span class="o">=</span> <span class="n">digits</span><span class="o">.</span><span class="n">target</span><span class="p">[</span><span class="n">n_samples</span><span class="o">/</span><span class="mi">2</span><span class="p">:]</span> <span class="n">predicted</span> <span class="o">=</span> <span class="n">classifier</span><span class="o">.</span><span class="n">predict</span><span class="p">(</span><span class="n">data</span><span class="p">[</span><span class="n">n_samples</span><span class="o">/</span><span class="mi">2</span><span class="p">:])</span> <span class="k">print</span> <span class="s">"Classification report for classifier:"</span> <span class="k">print</span> <span class="n">classifier</span> <span class="k">print</span> <span class="k">print</span> <span class="n">classification_report</span><span class="p">(</span><span class="n">expected</span><span class="p">,</span> <span class="n">predicted</span><span class="p">)</span> <span class="k">print</span> <span class="k">print</span> <span class="s">"Confusion matrix:"</span> <span class="k">print</span> <span class="n">confusion_matrix</span><span class="p">(</span><span class="n">expected</span><span class="p">,</span> <span class="n">predicted</span><span class="p">)</span> <span class="k">for</span> <span class="n">index</span><span class="p">,</span> <span class="p">(</span><span class="n">image</span><span class="p">,</span> <span class="n">prediction</span><span class="p">)</span> <span class="ow">in</span> <span class="nb">enumerate</span><span class="p">(</span> <span class="nb">zip</span><span class="p">(</span><span class="n">digits</span><span class="o">.</span><span class="n">images</span><span class="p">[</span><span class="n">n_samples</span><span class="o">/</span><span class="mi">2</span><span class="p">:],</span> <span class="n">predicted</span><span class="p">)[:</span><span class="mi">4</span><span class="p">]):</span> <span class="n">pl</span><span class="o">.</span><span class="n">subplot</span><span class="p">(</span><span class="mi">2</span><span class="p">,</span> <span class="mi">4</span><span class="p">,</span> <span class="n">index</span><span class="o">+</span><span class="mi">5</span><span class="p">)</span> <span class="n">pl</span><span class="o">.</span><span class="n">imshow</span><span class="p">(</span><span class="n">image</span><span class="p">,</span> <span class="n">cmap</span><span class="o">=</span><span class="n">pl</span><span class="o">.</span><span class="n">cm</span><span class="o">.</span><span class="n">gray_r</span><span class="p">)</span> <span class="n">pl</span><span class="o">.</span><span class="n">title</span><span class="p">(</span><span class="s">'Prediction: </span><span class="si">%i</span><span class="s">'</span> <span class="o">%</span> <span class="n">prediction</span><span class="p">)</span> <span class="n">pl</span><span class="o">.</span><span class="n">show</span><span class="p">()</span> </pre></div> </div> </div> </div> </div> </div> <div class="clearer"></div> </div> </div> <div class="footer"> <p style="text-align: center">This documentation is relative to scikits.learn version 0.6.0<p> © 2010, scikits.learn developers (BSD Lincense). 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