Getting confidence intervals on probabilities when doing ordinal logistic regression
<p>I have a data frame (training) that contains the following columns:</p>

<pre><code>       GPAGrpd    Subj1.Grade
1       [0,2)          6
2       [0,2)          6
3       [3,4.3]        1
4       [0,2)          6
5       [2,3)          2
6       [3,3.7)        3
</code></pre>

<p>I have run the following commands:</p>

<pre><code> Res.clm &lt;- clm(GPAGrpd ~ Subj1.Grade,data=training)
 summary(Res.clm)
 newdat &lt;- data.frame(
      Subj1.Grade = rep(1:6, each = 200),
      GPAGrpd = factor(rep(1:4, each = 300))
 )
 newdat &lt;- cbind(newdat, predict(Res.clm, newdata=newdat, se.fit=TRUE,
          interval=TRUE, type="prob"))
</code></pre>

<p>However, I get an error message that states: <code>Error in predict.clm(Res.clm, newdata = newdat, se.fit = TRUE, interval = TRUE,  : 
  response factor 'GPAGrpd' has new levels</code></p>