MATLAB: Overwrite matrix A with matrix B (which has another size)

different sizematrixoverwrite

Hi,
I would like to overwrite matrix_a with an extended matrix_b.
matrix_a has the dimension 19×57 and is full of data.
matrix_b = [zeros(1,57) matrix_a]
matrix_a = matrix_b;
matrix_a has to be updated and I use this matrix in a loop.
The Error: "Size mismatch (size [57 x 19] ~= size [57 x 20])."
Is there any way to overwrite matrix_a with another matrix with different size?
Thanks! Greeting

Best Answer

matrix_b = [zeros(1,57) matrix_a];
clear matrix_a
matrix_a = matrix_b;