BLAS utilities

Detailed Description

Utilities for the BLAS/LAPACK interface.

Typedefs
using	nda::dcomplex = std::complex<double>
	Alias for std::complex<double> type.

Functions
template<Array A> requires (MemoryArray<A> or is_conj_array_expr<A>)
MemoryArray decltype(auto)	nda::blas::get_array (A &&a)
	Get the underlying array of a conjugate lazy expression or return the array itself in case it is an nda::MemoryArray.
template<MemoryArray A> requires (get_rank<A> == 1 or get_rank<A> == 2)
int	nda::blas::get_ld (A const &a)
	Get the leading dimension of an nda::MemoryArray with rank 1 or 2 for BLAS/LAPACK calls.
template<MemoryArray A> requires (get_rank<A> == 1 or get_rank<A> == 2)
int	nda::blas::get_ncols (A const &a)
	Get the number of columns of an nda::MemoryArray with rank 1 or 2 for BLAS/LAPACK calls.

Variables
template<Array A>
static constexpr char	nda::blas::get_op
	Variable template that determines the BLAS matrix operation tag ('N','T','C') based on the given boolean flags for conjugation and transposition.
template<Array A>
static constexpr bool	nda::blas::has_C_layout
	Constexpr variable that is true if the given nda::Array type has nda::C_layout.
template<Array A>
static constexpr bool	nda::blas::has_F_layout
	Constexpr variable that is true if the given nda::Array type has nda::F_layout.
template<typename A>
static constexpr bool	nda::blas::is_conj_array_expr = false
	Constexpr variable that is true if the given type is a conjugate lazy expression.
template<MemoryArray A>
static constexpr bool	nda::blas::is_conj_array_expr< expr_call< detail::conj_f, A > > = true
	Specialization of nda::blas::is_conj_array_expr for the conjugate lazy expressions.

Function Documentation

get_array()

template<Array A>
requires (MemoryArray<A> or is_conj_array_expr<A>)

MemoryArray decltype(auto) nda::blas::get_array

(

A &&

a

)

#include <nda/blas/tools.hpp>

Get the underlying array of a conjugate lazy expression or return the array itself in case it is an nda::MemoryArray.

Template Parameters

A	nda::Array type.

Parameters

a	Conjugate expression or array/view.

Returns

nda::MemoryArray object.

Definition at line 62 of file tools.hpp.

get_ld()

template<MemoryArray A>
requires (get_rank<A> == 1 or get_rank<A> == 2)

int nda::blas::get_ld

(

A const &

a

)

#include <nda/blas/tools.hpp>

Get the leading dimension of an nda::MemoryArray with rank 1 or 2 for BLAS/LAPACK calls.

The leading dimension is the stride between two consecutive columns (rows) of a matrix in Fortran (C) layout. For 1-dimensional arrays, we simply return the size of the array.

Template Parameters

A	nda::MemoryArray type.

Parameters

a	nda::MemoryArray object.

Returns

Leading dimension for BLAS/LAPACK calls.

Definition at line 122 of file tools.hpp.

get_ncols()

template<MemoryArray A>
requires (get_rank<A> == 1 or get_rank<A> == 2)

int nda::blas::get_ncols

(

A const &

a

)

#include <nda/blas/tools.hpp>

Get the number of columns of an nda::MemoryArray with rank 1 or 2 for BLAS/LAPACK calls.

The number of columns corresponds to the extent of the second (first) dimension of a matrix in Fortran (C) layout. For 1-dimensional arrays, we return 1.

Template Parameters

A	nda::MemoryArray type.

Parameters

a	nda::MemoryArray object.

Returns

Number of columns for BLAS/LAPACK calls.

Definition at line 142 of file tools.hpp.

Variable Documentation

get_op

template<Array A>

char nda::blas::get_op

staticconstexpr

#include <nda/blas/tools.hpp>

Initial value:

= []() {
    auto constexpr conj      = is_conj_array_expr<A>;
    auto constexpr transpose = has_C_layout<A>;
    static_assert(!(conj and not transpose), "Error in nda::blas::get_op: Cannot use conjugate operation alone in BLAS operations");
    if constexpr (conj and transpose)
      return 'C';
    else if constexpr (transpose)
      return 'T';
    else 
      return 'N';
  }()

Variable template that determines the BLAS matrix operation tag ('N','T','C') based on the given boolean flags for conjugation and transposition.

Template Parameters

conj	Boolean flag for conjugation.
transpose	Boolean flag for transposition.

Definition at line 98 of file tools.hpp.