Jun 23, 2011
So I have a column in the data table and want to generate a new column with the value the summation of the first column to the current row. For example:
Summation(i=1,Row(),:C1 works, but it is quite wasteful and slow for long columns.
Match(Row(), 1, :C1, Lag(:C2, 1) + :C1) works well so far, even the treatment of the first row is again wasted for the other million rows.
Is there a built-in function for this? Any better ways?
Mar 28, 2013
try this formula:
If( Row() == 1,
Lag( :Column 2, 1 ) + :Column 1
In row 1, it copies the value from column 1
for all other rows, it looks at the previous value in the same column 2, and adds the value from column 1 in the current row