问题
Im starting to use BLAS functions in c++ (specifically intel MKL) to create faster versions of some of my old Matlab code.
Its been working out well so far, but I cant figure out how to perform elementwise multiplication on 2 matrices (A .* B in Matlab).
I know gemv does something similar between a matrix and a vector, so should I just break one of my matrices into vectprs and call gemv repeatedly? I think this would work, but I feel like there should be aomething built in for this operation.
回答1:
Use the Hadamard product. In MKL it's v?MUL. E.g. for doubles:
vdMul( n, a, b, y );
in Matlab notation it performs:
y[1:n] = a[1:n] .* b[1:n]
In your case you can treat matrices as vectors.
来源：https://stackoverflow.com/questions/23794763/element-wise-multiplication-between-matrices-in-blas