Unfortunately, the Col Quantile function does not support a By variable. However, you can use the following formulas to get around this limitation:
//Examples using $SAMPLE_DATA/Big Class.jmp:
//When By variable is character-valued:
Quantile( 0.25, (:height << get values)[loc((:sex << get values),"M")] )
//When By variable is numeric-valued:
Quantile( 0.25, (:height << get values)[loc((:age << get values) == :age)] )
Hopefully, one of these two will work for your situation!
Michael
Michael Crotty
Principal Statistical Writer
Manager, Statistical Documentation
JMP Development