Depending on what you are trying to do in the end, here is one option how you could modify the script
Names Default To Here(1);
dt = Open("$sample_data\Big Class.jmp");
numcols = dt << get column names(numeric, string);
rpt = New Window("Big Class - Decision Tree of sex",
dt << Partition(
Y(:sex),
X(Eval(numcols)),
Informative Missing(1),
SendToReport(Dispatch({}, "Candidates", OutlineBox, {Close(0)}))
)
);
dt_candidates = rpt["Partition for sex", "Candidates", Table Box(1)] << Make Into Data Table;
-Jarmo