BlasL2SyMV

Computes a matrix-vector product for a symmetric n-by-n matrix.

y = alpha*A*x + beta*y

BLAS function SYMV.

Computing for type matrix<double>

bool  matrix::BlasL2SyMV(
   double          alpha,         // scalar multiplier alpha
   vector&         X,             // vector X
   double          beta,          // scalar multiplier beta
   vector&                      // result vector Y
   );

Computing for type matrix<float>

bool  matrixf::BlasL2SyMV(
   float           alpha,         // scalar multiplier alpha
   vectorf&        X,             // vector X
   float           beta,          // scalar multiplier beta
   vectorf&                     // result vector Y
   );

Parameters

alpha

[in]  Scalar multiplier alpha.

X

[in]  Vector x of size n.

beta

[in]  Scalar multiplier beta.

Y

[in, out]  Result vector y of size n. If beta is not zero, then vector Y should contain actual data before entry.If vector size differs from n, then vector Y will be resized and zeroed.

Return Value

Return true if successful, otherwise false in case of an error.

Note

The input can be a symmetric, upper triangular or lower triangular matrix. Triangular matrices are assumed to be symmetric.