title: Unable to specify type="response" in Caret's predict function
body: <p>I am trying to plot a ROC curve for my <code>glmnet</code> regression model. In order to do that, I am trying to predict using type = "response" in predict function: </p>
  
  <pre><code> pred_glmnet_s10_2class &lt;- predict(model_train_glmnet_s10_2class,
                                     newdata=testing_s10_2class,
                                     s = "model_train_glmnet_s10_2class$finalModel$lambdaOpt",
                                     type="response")
  </code></pre>
  
  <p>and I get the following error:</p>
  
  <blockquote>
    <p>Error in predict.train(model_train_glmnet_s10_2class, newdata =  testing_s10_2class,  : 
         type must be either "raw" or "prob"</p>
  </blockquote>
  
  <p>My predictions and class labels are binary 0 and 1 and have been factored. Any help is really appreciated. Also, any ideas on how to plot AUC (Area Under ROC curve) vs number of features? Thanks!</p>