Create a larger matrix in special case [closed]

Answer 1

I'm assuming that A and B are coordinates, and you want to "draw" the plot in matrix form, so try this:

c = flipud(full(sparse(B, A, B)));

I added flipud to adjust the positive direction of the y-axis upwards.

Alternatively, you can obtain a binary matrix using this:

c1 = flipud(full(sparse(B, A, ones(size(A)))));

Important: for this solution to work, A and B must contain positive integer values. There is no sense in try to "plot" a matrix with non-positive or non-integer positions.

Example

A = 1:4; B = [3, 4, 3, 4];   
c = flipud(full(sparse(B, A, B)))
c1 = flipud(full(sparse(B, A, ones(size(A)))))

This results in:

c =
     0     4     0     4
     3     0     3     0
     0     0     0     0
     0     0     0     0

c1 =
     0     1     0     1
     1     0     1     0
     0     0     0     0
     0     0     0     0