topic Re: How do I manipulate column formulae in data tables by scripting? in Discussions

How do I manipulate column formulae in data tables by scripting?

PowerOx327 — Sat, 10 Jun 2023 23:52:05 GMT

Hi,

I'm trying to add a formula to convert values in a selected column through scripting without having to add any new columns in the data table, is there a way to edit formulas for a column by scripting? For example I'm trying to set the height column in this data table to be halved when I run the script:

Names Default To Here( 1 );
Open( "$SAMPLE_DATA/Big Class.jmp" );
Current Data Table() << Get Column Names;
height = height/2;

Re: How do I manipulate column formulae in data tables by scripting?

Mark_Bailey — Thu, 28 Jul 2022 13:17:34 GMT

A data column formula is just a JSL expression that is evaluated row-wise. You can use the data column messages << Get Formula() and << Set Formula(). Use expression functions to access and modify the expressions as needed.

Re: How do I manipulate column formulae in data tables by scripting?

txnelson — Thu, 28 Jul 2022 13:45:14 GMT

Your specified formula is recursive when used as a column formula. A column formula will run whenever it detects a change in the column.

What you are suggesting can simply be done in open JSL.

Names Default To Here( 1 );
Open( "$SAMPLE_DATA/Big Class.jmp" );
Current Data Table() << Get Column Names;
height = height/2;

Names Default To Here( 1 );
Open( "$SAMPLE_DATA/Big Class.jmp" );
For( i = 1, i <= N Rows( current data table() ), i++,
	:height[i] = :height[i] / 2
);

Names Default To Here( 1 );
dt = Open( "$SAMPLE_DATA/Big Class.jmp" );
dt:Height << set values( dt[0, 4] / 2 );

If the formula isn't recursive, one can set the column formula by using the Set Formula message

Names Default To Here( 1 );
Open( "$SAMPLE_DATA/Big Class.jmp" );
Current Data Table() << Get Column Names;
:height << set formula(:weight/2);

I strongly suggest that you take the time to read the Scripting Guide available in the JMP Documentation Library under the Help pull down menu