how do I standardize a variable (in this case reaction time data) by another variable (participant)? I tried by looking at the distribution of the first variable by the second variable but did not find such a function and the normal standardize function does not give the option to do it by another variable. Every help would be very much appreiciated!
All you need to do to solve this issue, is to use the formula for standardizing the data. The formula for the standardization contains column functions that have the "By" calculation. So here is an example script that does what you want. It is standardizing to a mean of 100 and and std of 10
Names Default To Here( 1 );
dt = Open( "$SAMPLE_DATA/Big Class.jmp" );
dt << New Column( "standard by sex",
new mean = 100;
new STD = 10;
((:height - Col Mean( :height, :sex )) / Col Std Dev( :height, :sex )) * new STD