product (matrix-vector)

Header: <pressio/ops.hpp>

API

namespace pressio { namespace ops{

// op(A) = A
template <
  class A_type, class x_type, class y_type,
  class alpha_t, class beta_t
>
void product(::pressio::nontranspose /*unused*/,
      const alpha_t & alpha,
      const A_type & A,
      const x_type & x,
      const beta_t & beta,
      y_type & y);

// op(A) = A , construct result
template <
  class y_type, class A_type, class x_type, class alpha_t
>
y_type product(::pressio::nontranspose mode,
      const alpha_t & alpha,
      const A_type & A,
      const x_type & x);

// op(A) = A^T
template <
  class y_type, class A_type, class x_type, class alpha_t
>
void product(::pressio::transpose /*unused*/,
      const alpha_t & alpha,
      const A_type & A,
      const x_type & x,
      const beta_t & beta,
      y_type & y);

// op(A) = A^T , construct result
template <class y_type, class A_type, class x_type, class alpha_t>
y_type product(::pressio::transpose mode,
      const alpha_t & alpha,
      const A_type & A,
      const x_type & x);

}} // end namespace pressio::ops

Description

  • Performs matrix-vector multiplication according to y = beta * y + alpha * op(A) * x * op(A) indicates either A or A^T

  • alpha_t and beta_t are scalar types

  • x_type and y_type are rank-1 containers

  • A_type is a rank-2 container

  • The following combinations of container types are supported for each A_type:

    • Eigen

      • All container types are either Eigen containers or Pressio expressions of Eigen containers,

    • Kokkos

      • All container types are either Kokkos views or Pressio expressions of Eigen views

    • Teuchos (does not support constructed results)

      • A_type is a rank-2 Teuchos container

      • x_type and y_type are rank-1 Eigen containers

    • Tpetra

      • A_type is a rank-2 Tpetra container

      • x_type is a rank-1 Eigen, Kokkos, Teuchos, or Tpetra container

      • y_type is a rank-1 container. If x_type is Tpetra, it may be either a Kokkos or Eigen container (or a Pressio expression of a Kokkos or Eigen container) Otherwise, y_type is a Tpetra container or a Pressio column expression

    • Tpetra Block

      • A_type is a rank-2 Tpetra Block container

      • x_type is a rank-1 Eigen, Kokkos, Teuchos, or Tpetra Block container

      • y_type is a rank-1 container. If x_type is a Tpetra Block vector, y_type may be either an Eigen vector or a rank-1 Kokkos view Otherwise, y_type is a Tpetra Block vector or column expression