How to reduce size of matrix from 100 by 15 to 15 by 15

I have a 100(rows) by 15 (coloumns). I want to make a 15 by 15 matrix by taking average or something. How can it be done?

Thank you

[Rik]

Presumably you want to do somthing with the result. It might matter to determine the appropriate strategy.

What kind of average were you thinking of? Some sort of moving window average? Or perhaps you want to fit a surface to your array and interpolate the result?

[Jeffrey Clark]

@SHUBHAM AGARWAL, looking at the corrcoef for the 100x15 and just a plot of these shows a strong correlation between the columns but not as much between the rows. You may be better off with reducing to a 100x1 with polynomials representing the differences for the other 14 columns: 100+14*3=142 vs 225 (15x15). This is the plot of col1 vs 2-15: