Implementing faster python inner product with BLAS
Per @Pietro Saccardi:
int dgemv_(char *trans, integer *m, integer *n, doublereal * alpha, doublereal *a, integer *lda, doublereal *x, integer *incx, doublereal *beta, doublereal *y, integer *incy)...Y - DOUBLE PRECISION array of DIMENSION at least ( 1 + ( m - 1 )*abs( INCY ) ) when TRANS = 'N' or 'n' and at least ( 1 + ( n - 1 )*abs( INCY ) ) otherwise. Before entry with BETA non-zero, the incremented array Y must contain the vector y. On exit, Y is overwritten by the updated vector y.I doubt you can use NULL for Y in the call.