NAG CPP Interface
nagcpp::blas::dgemm (f06ya)

1 Purpose

2 Specification

#include "f06/nagcpp_f06ya.hpp"

template <typename A, typename B, typename C>

void function dgemm(const string transa, const string transb, const double alpha, const A &a, const B &b, const double beta, C &&c, OptionalF06YA opt)

template <typename A, typename B, typename C>

void function dgemm(const string transa, const string transb, const double alpha, const A &a, const B &b, const double beta, C &&c)

3 Description

4 References

5 Arguments

1: $\mathbf{transa}$ – string Input

On entry: specifies whether the operation involves $A$ or $A^{\mathrm{T}}$.

$\mathbf{transa}=\text{'N'}$

The operation involves $A$.

$\mathbf{transa}=\text{'T'}$ or $\text{'C'}$

The operation involves $A^{\mathrm{T}}$.

Constraint: $\mathbf{transa}=\text{'N'}$, $\text{'T'}$ or $\text{'C'}$.

2: $\mathbf{transb}$ – string Input

On entry: specifies whether the operation involves $B$ or $B^{\mathrm{T}}$.

$\mathbf{transb}=\text{'N'}$

The operation involves $B$.

$\mathbf{transb}=\text{'T'}$ or $\text{'C'}$

The operation involves $B^{\mathrm{T}}$.

Constraint: $\mathbf{transb}=\text{'N'}$, $\text{'T'}$ or $\text{'C'}$.

3: $\mathbf{alpha}$ – double Input

On entry: the scalar $\alpha$.

4: $\mathbf{a}(:,:)$ – double array Input

Note: the first dimension of a is given by: if $\mathbf{transa}=\text{"N"}$: $\mathbf{m}$; if $\mathbf{transa}=\text{"T"}\text{\hspace{0.25em} or \hspace{0.25em}}\mathbf{transa}=\text{"C"}$: $\mathbf{k}$; otherwise: $0$.

Note: the second dimension of a is given by: if $\mathbf{transa}=\text{"N"}$: $\mathbf{k}$; if $\mathbf{transa}=\text{"T"}\text{\hspace{0.25em} or \hspace{0.25em}}\mathbf{transa}=\text{"C"}$: $\mathbf{m}$; otherwise: $0$.

On entry: the matrix $A$; $A$ is $m$ by $k$ if $\mathbf{transa}=\text{'N'}$, or $k$ by $m$ if $\mathbf{transa}=\text{'T'}$ or $\text{'C'}$.

5: $\mathbf{b}(:,:)$ – double array Input

Note: the first dimension of b is given by: if $\mathbf{transb}=\text{"N"}$: $\mathbf{k}$; if $\mathbf{transb}=\text{"T"}\text{\hspace{0.25em} or \hspace{0.25em}}\mathbf{transb}=\text{"C"}$: $\mathbf{n}$; otherwise: $0$.

Note: the second dimension of b is given by: if $\mathbf{transb}=\text{"N"}$: $\mathbf{n}$; if $\mathbf{transb}=\text{"T"}\text{\hspace{0.25em} or \hspace{0.25em}}\mathbf{transb}=\text{"C"}$: $\mathbf{k}$; otherwise: $0$.

On entry: the matrix $B$; $B$ is $k$ by $n$ if $\mathbf{transb}=\text{'N'}$, or $n$ by $k$ if $\mathbf{transb}=\text{'T'}$ or $\text{'C'}$.

6: $\mathbf{beta}$ – double Input

On entry: the scalar $\beta$.

7: $\mathbf{c}(\mathbf{m},\mathbf{n})$ – double array Input/Output

On entry: the $m$ by $n$ matrix $C$.

If $\mathbf{beta}=0.0$, c need not be set.

On exit: the updated matrix $C$.

8: $\mathbf{opt}$ – OptionalF06YA Input/Output

Optional parameter container, derived from Optional.

6 Exceptions and Warnings

Raises: ErrorException

$\mathbf{errorid}=1$

On entry, error in parameter transa.
Constraint: $\mathbf{transa}=\text{"N"},\text{"T"}\text{ or }\text{"C"}$.

$\mathbf{errorid}=2$

On entry, error in parameter transb.
Constraint: $\mathbf{transb}=\text{"N"},\text{"T"}\text{ or }\text{"C"}$.

$\mathbf{errorid}=3$

On entry, error in parameter $\mathbf{m}$.
Constraint: $\mathbf{m}\ge 0$.

$\mathbf{errorid}=4$

On entry, error in parameter $\mathbf{n}$.
Constraint: $\mathbf{n}\ge 0$.

$\mathbf{errorid}=5$

On entry, error in parameter $\mathbf{k}$.
Constraint: $\mathbf{k}\ge 0$.

$\mathbf{errorid}=10601$

On entry, argument $⟨\mathit{\text{value}}⟩$ must be a $⟨\mathit{\text{value}}⟩$ x $⟨\mathit{\text{value}}⟩$ array.
Supplied argument has $⟨\mathit{\text{value}}⟩$ dimensions.

$\mathbf{errorid}=10601$

On entry, argument $⟨\mathit{\text{value}}⟩$ must be a $⟨\mathit{\text{value}}⟩$ x $⟨\mathit{\text{value}}⟩$ array.
Supplied argument was a $⟨\mathit{\text{value}}⟩$ x $⟨\mathit{\text{value}}⟩$ array.

$\mathbf{errorid}=10601$

On entry, argument $⟨\mathit{\text{value}}⟩$ must be a $⟨\mathit{\text{value}}⟩$ x $⟨\mathit{\text{value}}⟩$ array.
Not all of the sizes for the supplied array could be ascertained.

$\mathbf{errorid}=10602$

On entry, the raw data component of $⟨\mathit{\text{value}}⟩$ is null.

$\mathbf{errorid}=10603$

On entry, unable to ascertain a value for $⟨\mathit{\text{value}}⟩$.

$\mathbf{errorid}=10604$

On entry, the data in $⟨\mathit{\text{value}}⟩$ is stored in $⟨\mathit{\text{value}}⟩$ Major Order.
The data was expected to be in $⟨\mathit{\text{value}}⟩$ Major Order.

$\mathbf{errorid}=-99$

An unexpected error has been triggered by this routine.

$\mathbf{errorid}=-999$

Dynamic memory allocation failed.

7 Accuracy

8 Parallelism and Performance

9 Further Comments

10 Example