I have a matrxi of 4*37800. I want to keep specific values based on two indeces.
The first index shows the rows that i want to keep and the second the columns every 15 steps. I mean that i split the 37800 columns to groups of 15 the index shows which column of each group i want to keep.
How can i isolate the values based on the two indeces?
I attach the folders.
iMxR is the index showing the rows that i want. ix is the index showing which colum i need. freq is the matrix.
Thank you for your help.