title: Error: some required components are missing: prob?
body: <p>I followed this guideline for creating my own caret model <a href="https://topepo.github.io/caret/using-your-own-model-in-train.html" rel="nofollow noreferrer">Creating Your Own Model</a>. There it states that </p>
  
  <blockquote>
    <p>If a regression model is being used or if the classification model
    does not create class probabilities a value of NULL can be used here
    instead of a function</p>
  </blockquote>
  
  <p>and so I do that</p>
  
  <pre><code># Define the model cFBasic
  cFBasic &lt;- list(type = "Regression",
                  library = c("lubridate", "stringr"),
                  loop = NULL)
  ...
  cFBasic$prob &lt;- NULL
  cFBasic$sort &lt;- NULL
  </code></pre>
  
  <p>However, when I attempt testing the model the following error is produced:</p>
  
  <pre><code>control &lt;- trainControl(method = "cv", 
                          number = 10, 
                          p = .9, 
                          allowParallel = TRUE)
  fit &lt;- train(x = calib_set,
               y = calib_set$y,
               method = cFBasic,
               trControl = control)
  Error: some required components are missing: prob
  </code></pre>
  
  <p>How can I fix that? other than adding the function prob to generate a fake <code>pro</code> data frame to make <code>caret</code> happy.</p>