topic Re: From Interpolation to Finding Closets Value in Discussions

From Interpolation to Finding Closets Value

Yngeinstn — Sat, 10 Jun 2023 23:32:00 GMT

I received some help long ago with trying to interpolate a -1 db Compression which worked flawlessly however the customer has changed their minds on the who interpolation thing. Now they just want the input value closest to the -1 db compression and then using that apply a spec limit to the Pout. I am looking for some assistance in trying to determine this point. Attached is a data table that has the raw data.

Grouping would be {"wafer_number", "RowCol", "input"} . There are 36 readings for each input at different compression values. I only need the closest to -1.

Thanks in advance

Re: From Interpolation to Finding Closets Value

brady_brady — Wed, 16 Jun 2021 22:24:53 GMT

Hi,

If you want to do this in the present table, you can add a formula column with the following formula, which compares each row's distance to -1 ( abs ( :compression - (-1))), which is (abs(:compression + 1)), to the minimum value found in the group.

Abs( :Compression + 1 ) == Col Minimum( Abs( :Compression + 1 ), :wafer_number, :RowCol, :input )

Thus, the rows in this column equaling 1 are the rows you want... you could select and subset them, etc.

If you want to directly subset without creating a new column, and don't mind using JSL, you could use this:

Names Default To Here(1);

dt = current data table();

dtSub = dt << subset(
	selected columns(0), 
	rows(dt << get rows where(Abs( :Compression + 1 ) == Col Minimum( Abs( :Compression + 1 ), :wafer_number, :RowCol, :input )))
);

Cheers,

Brady

Re: From Interpolation to Finding Closets Value

Yngeinstn — Thu, 17 Jun 2021 12:20:17 GMT

@brady_brady

Thank you very much for your help. I was sort of on the right track with the :Compression + 1 but didn't consider the absolute value. Works like a charm.