Select rows with maximal values in one column

[#1]

I can use summary to find the maximums (multiple due to groups) in one column. However, I also want to look up in which rows in the original table the maximums occur.

Is there an easy solution? Thanks for your help!

[#2]

Jeff,

Thanks. This appears to be new feature from JMP 9. I am using JMP 7. I guess I may request an upgrade.

Also, I am trying to select multiple maximums in one column. The maximums belong to different groups specified in other columns.

Dong

[#3 · Accepted solution]

I know this is two years later, but this is for all those who found this post with the same question.

Try the function "Get Selected Rows" in your script.

yourarray = dt << Get Selected Rows;

Now the array "yourarray" will contain a list of the row numbers that are selected.

To find the rows with the maximum value, try

// finds the maximum value in the columnt
peakvalue = Col Max( :columname); 

// selects all rows with the maximum value. (dt is the name of the data table.)
dt << Select Where( :columnname == peakvalue);

 // stores a list of the row numbers with the maximum value in this array
yourarray = dt << Get Selected Rows;    

[#4]

You can also use GET ROWS WHERE:

yourarray = dt << get rows where(:columnname == peakvalue);

The advantage of get rows where is that a) it's one step and not two, and b) no rows are selected in your table.  If you need the selected rows then the approach shown by MOSFETtestEng will do the trick.