title: Using mRMRe for feature selection with Categorical target variable
body: <p>I am trying to use the <code>mRMRe</code> package in R to do a feature selection on a gene expression dataset.</p>
  
  <p>My target variable is a categorical variable, i.e. each sample is associated to a class, which is used as target variable.</p>
  
  <p>However, by using the <code>mRMRe</code> package, I get the following error when I try to load the data:</p>
  
  <pre><code>data &lt;- mRMR.data(data = data)
  
  Error in .local(.Object, ...): data columns must be either of numeric, ordered factor or Surv type
  Traceback:
  
  1. mRMR.data(data = data)
  2. new("mRMRe.Data", ...)
  3. initialize(value, ...)
  4. initialize(value, ...)
  5. .local(.Object, ...)
  6. stop("data columns must be either of numeric, ordered factor or Surv type")
  </code></pre>
  
  <p>The first column has categorical labels, e.g. "Class1", "Class2", etc. When I use <code>str(data)</code> I get that the first column is of <code>Factor</code> type. However, it cannot be ordered because it is categorical.</p>
  
  <p>Could it be possible that <code>mRMRe</code> cannot handle categorical data?</p>