How do I replace the "classregtree" class and "eval" function in R2018a onwards?

I used to use "eval" in MATLAB R2017b, but this triggers an error in R2018a. I have looked in the documentation but found no solution. Can you help?

Error using eval
Too many input arguments.

Answer 1

[MathWorks Support Team]

That "eval" function was a method of the "classregtree" class which was removed in MATLAB R2018a. I noticed that you are now using the "fitctree" method instead of the removed "classregtree".

The trees from "fitctree" are part of the "ClassificationTree" class. A similar method to "eval" is in that class. It is called- "predict" and it predicts labels using classification tree. The third input in "predict" is slightly different than "eval", so you would need to change the inputs slightly.

Instead of:

>> eval(T, X, s)

The "predict" function should be used with the "Subtrees" Name-Value pair.

>> predict(T, X, 'Subtrees', s);

You can refer to the following MathWorks documentation for more information:

• ClassificationTree class
• predict function