NAG Library Routine Document

f06qff (dmcopy)

1

Purpose

2

Specification

3

Description

4

References

5

Arguments

1:     $\mathbf{matrix}$ – Character(1)Input

On entry: the matrix type.

$\mathbf{matrix}=\text{'G'}$

General matrix.

$\mathbf{matrix}=\text{'U'}$

Upper trapezoidal matrix (upper triangular if $m=n$).

$\mathbf{matrix}=\text{'L'}$

Lower trapezoidal matrix (lower triangular if $m=n$).

Constraint: $\mathbf{matrix}=\text{'G'}$, $\text{'U'}$ or $\text{'L'}$.

2:     $\mathbf{m}$ – IntegerInput

On entry: $m$, the number of rows of the matrices $A$ and $B$.

Constraint: $\mathbf{m}\ge 0$.

3:     $\mathbf{n}$ – IntegerInput

On entry: $n$, the number of columns of the matrices $A$ and $B$.

Constraint: $\mathbf{n}\ge 0$.

4:     $\mathbf{a}\left(\mathbf{lda},*\right)$ – Real (Kind=nag_wp) arrayInput

Note: the second dimension of the array a must be at least $\mathbf{n}$.

On entry: the $m$ by $n$ general or trapezoidal matrix $A$.

• If $\mathbf{matrix}=\text{'U'}$, $A$ is upper trapezoidal and the elements of the array below the diagonal are not referenced.
• If $\mathbf{matrix}=\text{'L'}$, $A$ is lower trapezoidal and the elements of the array above the diagonal are not referenced.

5:     $\mathbf{lda}$ – IntegerInput

On entry: the first dimension of the array a as declared in the (sub)program from which f06qff is called.

Constraint: $\mathbf{lda}\ge \max \left(1,\mathbf{m}\right)$.

6:     $\mathbf{b}\left(\mathbf{ldb},*\right)$ – Real (Kind=nag_wp) arrayOutput

Note: the second dimension of the array b must be at least $\mathbf{n}$.

On exit: the $m$ by $n$ general or trapezoidal matrix $B$.

• If $\mathbf{matrix}=\text{'U'}$, $B$ is upper trapezoidal and the elements of the array below the diagonal are not referenced.
• If $\mathbf{matrix}=\text{'L'}$, $B$ is lower trapezoidal and the elements of the array above the diagonal are not referenced.

7:     $\mathbf{ldb}$ – IntegerInput

On entry: the first dimension of the array b as declared in the (sub)program from which f06qff is called.

Constraint: $\mathbf{ldb}\ge \max \left(1,\mathbf{m}\right)$.

6

Error Indicators and Warnings

7

Accuracy

8

Parallelism and Performance

9

Further Comments

10

Example