Rarely, computational instability or a precision problem will result in a message stating that an "internal error" has been encountered. To help Salford Systems resolve the problem, please attempt the following:
- Rebuild as an exploratory tree to see if CART completes the building process.
- Rebuild the tree with a randomly-selected subset for testing (ERROR p=.2, for example).
- Rebuild a cross-validation tree with an explicit SEED to perturb the selection of cross-validation subsets.
Please send Salford Systems via email (or diskette):
- command files or commands used prior to the build;
- output generated during the run;
- frequency table of your target variable;
- frequency table of your categorical predictor variables; and
- if possible, your data set, or any subset that can reproduce the problem.