topic Re: Return the Row Number of Maximum in Discussions

Return the Row Number of Maximum

Hegedus — Thu, 11 Jan 2018 17:54:59 GMT

Hi,

Is it possible to get the row number of the maximum value of a column?

I would like to create a formula that uses a value in a column as an offset and I would like to write it in generic form such that it looks in Col1 for a maximum value and then returns the row number such I can use the value of col2 at that row number as the offset.

How could I do this?

Thanks in advance

Andy

Re: Return the Row Number of Maximum

txnelson — Thu, 11 Jan 2018 18:12:01 GMT

Here is a simple solution to your issue. It can be moved directly into a formula, or used in open code as it is shown:

names default to here(1);
dt=open("$SAMPLE_DATA\Semiconductor Capability.jmp" );

MaxRow=(dt<<get rows where(Col Maximum(:NPN1)==:NPN1))[1];
show(MaxRow);

Re: Return the Row Number of Maximum

cwillden — Thu, 11 Jan 2018 18:18:20 GMT

Col Max can return the max value in a column. Here's how you can find the row and use it to return the corresponding value in a different column using the Big Class sample data set:

dt = Current Data Table();

max_row = dt << Get Rows Where(:height == Col Max(:height));
dt:weight[max_row]

Re: Return the Row Number of Maximum

cwillden — Thu, 11 Jan 2018 18:19:10 GMT

Beat me to it.

Re: Return the Row Number of Maximum

Hegedus — Fri, 12 Jan 2018 00:20:16 GMT

Can I do this only using the formula editor?

Re: Return the Row Number of Maximum

cwillden — Fri, 12 Jan 2018 00:50:34 GMT

@Hegedus wrote:
Can I do this only using the formula editor?

Sure. Find the row with max value for column X1 and return the corresponding value for X2:

:X2[Current Data Table() << Get Rows Where( Col Maximum( :X1 ) == :X1 )]

You can copy that right into the formula editor and it will work.

Re: Return the Row Number of Maximum

Hegedus — Fri, 12 Jan 2018 01:06:05 GMT

Thank you!

Slightly tweaked but this is what I have and it seems to work.