08 Matrix Multiplication Instructionsl

08_matrix-matrix-multiplication_instructionsl

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Matrix-Matrix Multiplication

We multiply two matrices by breaking it into several vector multiplications and

concatenating the result.

An m x n matrix multiplied by an n x o matrix results in an m x o matrix. In the

above example, a 3 x 2 matrix times a 2 x 2 matrix resulted in a 3 x 2 matrix.

To multiply two matrices, the number of columns of the first matrix must equal

the number of rows of the second matrix.

For example:

% Initialize a 3 by 2 matrix

A = [1, 2; 3, 4;5, 6]

% Initialize a 2 by 1 matrix

B = [1; 2]

% We expect a resulting matrix of (3 by 2)*(2 by 1) = (3 by 1)

mult_AB = A*B

% Make sure you understand why we got that result