I want to execute a modified matrix multiplication where instead sum of product we obtain min of product.
classic matmult : (A@B)ij -> sum( Aik * Bkj for k in range(A.shape[1])
my custom matmult : (A@B)ij -> min( Aik * Bkj for k in range(A.shape[1])
My matrices are very large and in the scipy sparse format. This is why I need something smarter than calculate all positions.
THIS IS NOT A DUPLICATE of matrix multiplication but sum of min() instead of sum of product
The sparse @ uses a two stage calculation each writtem in cython (i.e. compiled). The comments reference a math paper from the 1990s, which should be well known in the sparse math community. It uses the CSR format.
Looks like SO’s ‘related questions’ has found some thing useful.
1) Can you give an example brute-force solution so answer writers have something to test against? 2) What is the format of these scipy sparse matricies? CSR? CSC? COO?