Displaying 1 result from an estimated 1 matches for "tp26376359p26378112".
2009 Nov 16
3
Sum over indexed value
I am sure this is easy but I am not finding a function to do this.
I have two columns in a matrix. The first column contains multiple entries
of numbers from 1 to 100 (i.e. 10 ones, 8 twos etc.). The second column
contains unique numbers. I want to sum the numbers in column two based on
the indexed values in column one (e.g. sum of all values in column two
associated with the value 1 in column