///////////////////////////////////////////////////////////////////////////////
//* performs a matrix-vector multiply with optional transposes BLAS version
void MultMv(const Matrix<double> &A, const Vector<double> &v, DenseVector<double> &c,
const bool At, double a, double b)
{
static char t[2] = {'N','T'};
char *ta=t+At;
int sA[2] = {A.nRows(), A.nCols()}; // sizes of A
int sV[2] = {v.size(), 1}; // sizes of v
GCK(A, v, sA[!At]!=sV[0], "MultAB<double>: matrix-vector multiply");
if (c.size() != sA[At])
{
c.resize(sA[At]); // set size of C to final size
c.zero();
}
// get pointers to the matrix sizes needed by BLAS
int *M = sA+At; // # of rows in op[A] (op[A] = A' if At='T' else A)
int *N = sV+1; // # of cols in op[B]
int *K = sA+!At; // # of cols in op[A] or # of rows in op[B]
double *pa=A.get_ptr(), *pv=v.get_ptr(), *pc=c.get_ptr();
#ifdef COL_STORAGE
dgemm_(ta, t, M, N, K, &a, pa, sA, pv, sV, &b, pc, M);
#else
dgemm_(t, ta, N, M, K, &a, pv, sV+1, pa, sA+1, &b, pc, N);
#endif
}
