How to double the size of a matrix and propagate its elements in Matlab?

matlab, matrix, size, vectorization

Solution

use `kron` - Kronecker tensor product:

kron(a,ones(2))


ans =
 1     1     2     2
 1     1     2     2
 3     3     4     4
 3     3     4     4

Problem

suppose I have a matrix like this: ``` a = 1 2 3 4 ``` I want to double the size of matrix and create something like this: ``` aa = 1 1 2 2 1 1 2 2 3 3 4 4 3 3 4 4 ``` in this way, each element in the first matrix propagates to four elements in the bigger matrix. ``` a(i,j) == aa(2*i-1, 2*j-1) == aa(2*i , 2*j-1) == aa(2*i-1, 2*j) == aa(2*i , 2*j) ``` is there any predefined functions to do that? definitely I can do that by two loops, but I want the easiest and cleanest way!

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