What if I cannot apply a tree to new data?
You wish to apply your results to new data, but CASE will not accept the data.
SOLUTION 1: Check For TR1 Tree File
Make sure the .TR1 tree file, in which CART stores the tree structure, variable list and category specifications, exists.
SOLUTION 2: Check Variable List on USE File
Every variable on the .TR1 tree file, except the target variable, must also exist on the USE file. The variables need not all have non-missing values, but they must exist. If the tree was originally grown with many extraneous variables of low or zero importance, you may wish to re-build the tree with a smaller MODEL list.Steinberg, Dan and Phillip Colla. CART—Classification and Regression Trees. San Diego, CA: Salford Systems, 1997.