This is my first post on the forum, because I've been having trouble trying to do this. How can I from an array that's [i][j] duplicate it's column and line values to a [2*i][2*j]?
For example : [2,4];[5,6] to [2,2,4,4];[2,2,4,4];[5,5,6,6];[5,5,6,6]
And how can I do the inverse, remove alternatively column and line.
For example: [1,2,3,4];[5,6,7,8];[9,10,11,12];[13,14,15,16] to [1,3];[9,11]