title: Error in .jcall("weka/filters/Filter", "Weka/core/Instances;", "useFilter", : java.lang.IllegalArgumentException:
body: <p>I am trying to execute the following code to filter features using mlr as shown in <a href="https://mlr-org.github.io/mlr-tutorial/release/html/feature_selection/index.html#filter-methods" rel="nofollow noreferrer">here</a></p>
  
  <pre><code>fv = generateFilterValuesData(classifTask,  method = c("information.gain", "chi.squared"))
  </code></pre>
  
  <p>But I get the following error <strong>although the specified attribute is numeric</strong> in the dataset Task(classifTask)</p>
  
  <blockquote>
    <p>Error in .jcall("weka/filters/Filter", "Weka/core/Instances;",
    "useFilter", : java.lang.IllegalArgumentException: A nominal attribute
    (weighted_rev) cannot have duplicate labels</p>
  </blockquote>
  
  <p>How can I fix this?</p>