Use of N Categories(:column) from Summary table for script computations

[#1]

Hi, I would like to inquire how to make use of N Categories(:X) resut in summary to make mathematical operations via script. It seems the :N Categories (:column) can not be used directly to do the computations, even if I rename or make another numeric column, blk_count. Here is what i have:

dt_ax = dt_X << Summary (

          Group (:abx),

          N Categories (:blk),

          Link to original table (0));

dt_X << Update (

          with (dt_ax),

          Match Columns(:abx = :abx),

          Ignore missing);

close(dt_ax, no save);

dt_X << New column("blk_count",

          Numeric,

          continuous,

          << set each value(blk_count == :N Categories( :blk ));

Appreciate all your inputs! Thanks in advance!

[#2 · Accepted solution]

This will give you the number of levels for a specified column:

dt_X<<new column("N Levels of blk", formula(

Summarize( x = by( :blk ) );

N Items( x );));

If you wanted to know how many rows are in each level then the Col Number function work:

Col Number( :blk, :blk )

[#3]

Thanks Byron for the help!