"How do I see actual vs. predicted from SVM Cross-Validation Setup?"

Answers

• SebastianLoh Member Posts: 99 Contributor II

  January 2011

  Hi Ghostrider,
  
  if you want to get the predictions out of a X-Validation you can replace X-Validation operator with a X-Prediction operator with the same setup.
  
  Just add X-prediction a SVM inside after your Parameter Optimizer, that uses the optimal parameter set. You can apply the calculated optimal parameter set like described in your other thread http://rapid-i.com/rapidforum/index.php/topic,3010.msg11922.html#msg11922
  
  The X-Prediction has a "lab" port which deliveres the labeled data.
  
  Ciao Sebastian

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• Ghostrider Member Posts: 60 Contributor II

  January 2011

  X-Prediction does return labels, but the problem is that it does not return a performance vector that can by used by the Optimization Process.  Is there an example that uses X-Prediction with parameter optimization?
  
  Also, how do I save the best, optimal model from the X-Validation / X-Prediction run?  There's no output port for model from validation operator.

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• IngoRM Administrator, Moderator, Employee, RapidMiner Certified Analyst, RapidMiner Certified Expert, Community Manager, RMResearcher, Member, University Professor Posts: 1,751 RM Founder

  January 2011

  Hi,
  
  this certainly is one of the most often answered questions in this forum (and even more in the old one at SourceForge a long time ago...). Fortunately I took some time to answer it in more detail one of the last times somebody asked the famous "What's the best model of my cross validation?" question. So here we go with a short link only today:
  
  http://rapid-i.com/rapidforum/index.php/topic,62.msg1264.html
  
  Hope that helps,
  Ingo

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• Ghostrider Member Posts: 60 Contributor II

  January 2011

  Hi Ingo,
  Thanks for your response.  I may not have had the right understanding of how cross-validation is used.  I thought that CV simply trains a model based on part of the data and then tests the other part of data with the model in order to assess accuracy.  So I was thinking that the cross validation operator would have a port to return the model if desired.  What I want to see are the predicted vs. actual data for the test example set (actually, I'd be interested in seeing the entire data set too) where the predicted values are predicted from an SVM trained using the parameters found by optimal prediction operator.  From Sebastian's post, I think the XML below is how one sets it up.  Can someone tell me if this looks right:

  
  <?xml version="1.0" encoding="UTF-8" standalone="no"?>
  <process version="5.1.001">
    <context>
      <input/>
      <output/>
      <macros/>
    </context>
    <operator activated="true" class="process" compatibility="5.0.000" expanded="true" name="Root">
      <description>&lt;p&gt; Often the different operators have many parameters and it is not clear which parameter values are best for the learning task at hand. The parameter optimization operator helps to find an optimal parameter set for the used operators. &lt;/p&gt;  &lt;p&gt; The inner crossvalidation estimates the performance for each parameter set. In this process two parameters of the SVM are tuned. The result can be plotted in 3D (using gnuplot) or in color mode. &lt;/p&gt;  &lt;p&gt; Try the following: &lt;ul&gt; &lt;li&gt;Start the process. The result is the best parameter set and the performance which was achieved with this parameter set.&lt;/li&gt; &lt;li&gt;Edit the parameter list of the ParameterOptimization operator to find another parameter set.&lt;/li&gt; &lt;/ul&gt; &lt;/p&gt; </description>
      <process expanded="true" height="584" width="962">
        <operator activated="true" class="retrieve" compatibility="5.0.000" expanded="true" height="60" name="Retrieve" width="90" x="45" y="30">
          <parameter key="repository_entry" value="../../data/Polynomial"/>
        </operator>
        <operator activated="true" class="optimize_parameters_grid" compatibility="5.0.000" expanded="true" height="112" name="ParameterOptimization" width="90" x="179" y="30">
          <list key="parameters">
            <parameter key="SVM.C" value="[0.0;Infinity;10;linear]"/>
            <parameter key="SVM.nu" value="[0.0;0.5;10;linear]"/>
            <parameter key="SVM.epsilon" value="[-Infinity;Infinity;10;linear]"/>
          </list>
          <process expanded="true" height="554" width="582">
            <operator activated="true" class="x_prediction" compatibility="5.1.001" expanded="true" height="60" name="X-Prediction" width="90" x="45" y="30">
              <process expanded="true" height="572" width="275">
                <operator activated="true" class="support_vector_machine_libsvm" compatibility="5.1.001" expanded="true" height="76" name="SVM" width="90" x="112" y="30">
                  <parameter key="svm_type" value="epsilon-SVR"/>
                  <parameter key="C" value="NaN"/>
                  <parameter key="nu" value="0.0"/>
                  <parameter key="epsilon" value="NaN"/>
                  <list key="class_weights"/>
                </operator>
                <connect from_port="training" to_op="SVM" to_port="training set"/>
                <connect from_op="SVM" from_port="model" to_port="model"/>
                <portSpacing port="source_training" spacing="0"/>
                <portSpacing port="sink_model" spacing="0"/>
                <portSpacing port="sink_through 1" spacing="0"/>
              </process>
              <process expanded="true" height="572" width="275">
                <operator activated="true" class="apply_model" compatibility="5.1.001" expanded="true" height="76" name="Apply Model" width="90" x="45" y="30">
                  <list key="application_parameters"/>
                </operator>
                <connect from_port="model" to_op="Apply Model" to_port="model"/>
                <connect from_port="unlabelled data" to_op="Apply Model" to_port="unlabelled data"/>
                <connect from_op="Apply Model" from_port="labelled data" to_port="labelled data"/>
                <portSpacing port="source_model" spacing="0"/>
                <portSpacing port="source_unlabelled data" spacing="0"/>
                <portSpacing port="source_through 1" spacing="0"/>
                <portSpacing port="sink_labelled data" spacing="0"/>
              </process>
            </operator>
            <operator activated="true" class="performance" compatibility="5.1.001" expanded="true" height="76" name="Performance" width="90" x="179" y="30"/>
            <operator activated="true" class="log" compatibility="5.0.000" expanded="true" height="76" name="Log" width="90" x="313" y="30">
              <parameter key="filename" value="paraopt.log"/>
              <list key="log">
                <parameter key="C" value="operator.Training.parameter.C"/>
                <parameter key="degree" value="operator.Training.parameter.degree"/>
                <parameter key="absolute" value="operator.Validation.value.performance"/>
              </list>
            </operator>
            <connect from_port="input 1" to_op="X-Prediction" to_port="example set"/>
            <connect from_op="X-Prediction" from_port="labelled data" to_op="Performance" to_port="labelled data"/>
            <connect from_op="Performance" from_port="performance" to_op="Log" to_port="through 1"/>
            <connect from_op="Performance" from_port="example set" to_port="result 1"/>
            <connect from_op="Log" from_port="through 1" to_port="performance"/>
            <portSpacing port="source_input 1" spacing="0"/>
            <portSpacing port="source_input 2" spacing="0"/>
            <portSpacing port="sink_performance" spacing="0"/>
            <portSpacing port="sink_result 1" spacing="0"/>
            <portSpacing port="sink_result 2" spacing="0"/>
          </process>
        </operator>
        <connect from_op="Retrieve" from_port="output" to_op="ParameterOptimization" to_port="input 1"/>
        <connect from_op="ParameterOptimization" from_port="performance" to_port="result 1"/>
        <connect from_op="ParameterOptimization" from_port="result 1" to_port="result 2"/>
        <portSpacing port="source_input 1" spacing="0"/>
        <portSpacing port="sink_result 1" spacing="0"/>
        <portSpacing port="sink_result 2" spacing="0"/>
        <portSpacing port="sink_result 3" spacing="0"/>
      </process>
    </operator>
  </process>
  

  Ingo, I apologize if I asked the question without doing enough research.  I don't mean to come here and mooch off people without giving anything back.  So how about this.  I made a join operator that takes multiple example sets and joins the data based on the common column ID (column ID must match, be ordered the same across all example sets, and each table must be of the same size) so the usefulness of this operator is more restricted than the general join operator, but if you think this would be a useful operator to contribute (not covered by existing operators), then I'd be happy to share my code.  Let me know what you think.

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