nag_sparse_herm_matvec (f11xsc) computes the matrix-vector product
where
is an
by
complex Hermitian sparse matrix, of arbitrary sparsity pattern, stored in symmetric coordinate storage (SCS) format (see
Section 2.1.2 in the f11 Chapter Introduction). The array
a stores all the nonzero elements in the lower triangular part of
, while arrays
irow and
icol store the corresponding row and column indices respectively.
None.
The computed vector
satisfies the error bound
where
is a modest linear function of
, and
is the
machine precision.
Please consult the
x06 Chapter Introduction for information on how to control and interrogate the OpenMP environment used within this function. Please also consult the
Users' Note for your implementation for any additional implementation-specific information.
The time taken for a call to
nag_sparse_herm_matvec (f11xsc) is proportional to
nnz.