Counting formula to identify different groups in timed data

Question

I have timed data (Turn-up Time) I used to create a Time Differnce column to easily identify different run sequences.  What I am struggling with is how to use this to creat a new column (Run Number) that automatically groups the data.  Ideas?

txnelson · Accepted Answer

This script should do the trick:

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

dt << New Column( "Run Number",
	character,
	formula(
		If( Row() == 1, runnum = 1 );
		If( :Time Difference Min > Col Mean( :Time Difference Min ) + Col Std Dev( :Time Difference Min ),
			runnum = runnum + 1
		);
		runnum;
	)
);