使用BLAS将实矩阵与复矢量相乘

Question

How can I use Blas to multiply a real matrix with a complex vector ? When I use functions like ccsrgemv() I get type mismatch errors?

error: argument of type "float *" is incompatible with parameter of type "std::complex<float> *"

Answer 1

Use two matrix-vector multiplications (A * (x + iy) = A * x + i A * y). More precisely, consider your complex vector as two entangled real vectors with stride 2. BLAS lets you do this.

UPDATE : actually, I did not notice that you were doing Sparse BLAS. For dgemv my trick works, but for csrgemv it doesn't. I'm afraid you have to maintain real and imaginary part separately.