Outlier Deletion

[#1]

Is there a way to script the deletion of extreme outliers per column? My objective is once i run the script, it concatenates data tables, delete extreme outliers per column and display graphs but im having some sort of problem with the outlier part.

[#2 · Accepted solution]

I use Jackknife Distances for outliers.

For extreme outliers I use upper limit = 6.

In the following example I use upper limit = 2.

Names Default To Here( 1 );
dt = Open( "$SAMPLE_DATA/Big Class.jmp" );
JackknifeObj = dt << Multivariate( Y( 4 ), Jackknife Distances( 1, Save Jackknife Distances( 1 ) ) );
JackknifeObj << Close Window();
dt << Select Where( :Jackknife Distances > 2 );
dt << Hide and Exclude << Clear Select << Delete Column( Jackknife Distances );

[#3]

@tom_abramov approach is a good method for identifying outliers. Are you looking for what method to use to identify outliers or do you already have a method of determining the outliers that you want to use?