How to select columns from a matrix with an algorithm
The column index i should satisfy 0 =< i modulo (210+70) <= 70-1
I am writing a user defined function in python to extract specific chunks of columns from a matrix efficiently.
My matrix is 48 by 16240. The data is organised in some pattern column wise.
My objective is to make 4 matrices out of it. The first matrix is extracted by selecting the first 70 columns, skip the next 210, select the next 70, skip the next 210, till the end of the matrix. 
The second matrix is extracted by selecting the second 70 columns, skip the next 210, select the next 70, skip the next 210, till the end of the matrix.
The third and the fourth matrix are extracted by selecting the third and the fourth 70 columns respectively, in the same manner as described above.
As can be observed, 16240 is dividable by 70. 
Is there a way to have this efficiently done?