topic Delete all columns that have zeros in all raws in Discussions

Delete all columns that have zeros in all raws

gallardet — Wed, 10 Jul 2019 20:13:56 GMT

Well, that is what I need to do.

I tried to look for similar scripts but I have not found the solution.

Thanks in advance.

Manel

Re: Delete all columns that have zeros in all raws

ron_horne — Wed, 10 Jul 2019 21:43:21 GMT

Hi @gallardet

for starters try this:

https://community.jmp.com/t5/Discussions/Select-and-Delete-a-Column-Where-All-Rows-Have-The-Same-Value/m-p/62142/highlight/true#M33477

ron

Re: Delete all columns that have zeros in all raws

txnelson — Wed, 10 Jul 2019 21:52:40 GMT

Here is a simple script that will delete all columns that are all zeros

Names Default To Here( 1 );
dt = Current Data Table();

numericColNames = dt << get column names( string, numeric );

allZerosList = {};

For( i = 1, i <= N Items( numericColNames ), i++,
	If( Col Sum( Column( dt, numericColNames[i] ) ) == 0
	& Col Std Dev( Column( dt, numericColNames[i] ) ) == 0,
		Insert Into( allZerosList, numericColNames[i] )
	)
);

If( N Items( allZerosList ) > 0,
	dt << delete columns( allZerosList )
);

Re: Delete all columns that have zeros in all raws

gallardet — Thu, 11 Jul 2019 18:55:39 GMT

Thanks, Sir.

Re: Delete all columns that have zeros in all raws

TRR21 — Thu, 18 Jul 2019 18:15:25 GMT

Can this be tweaked such that I can remove columns that have mostly zeros (eg. 50% of more of the rows)?

Thanks.

Re: Delete all columns that have zeros in all raws

txnelson — Fri, 19 Jul 2019 01:32:22 GMT

You could do something like:

If(
	N Rows( dt << get rows where( Column( dt, numericColNames[i] ) == 0 ) ) >
	N Rows( dt ) / 2,
	Insert Into( allZerosList, numericColNames[i] )
);