How to Multiply Matrices: Columns Times Rows

Описание: Try this method for matrix multiplication, which multiplies columns with rows. Matrix multiplication can be written as the sum of rank-1 matrices. A rank-1 matrix is a matrix where each column is a multiple of the first column. Rank-1 matrices are simple building blocks that combine to create more complex matrices.

The sum of rank-1 matrices appears in the singular value decomposition (SVD) of a matrix. In the SVD each rank-1 matrix has an associated singular value that describes its contribution to the decomposition.