NAG FL Interface
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: $\mathbf{m}$ – Integer Input

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

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

3: $\mathbf{n}$ – Integer Input

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

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

4: $\mathbf{a}(\mathbf{lda},*)$ – Real (Kind=nag_wp) array Input

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

On entry: the $m\times n$ 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: $\mathbf{lda}$ – Integer Input

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

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

6: $\mathbf{b}(\mathbf{ldb},*)$ – Real (Kind=nag_wp) array Output

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

On exit: the $m\times n$ 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: $\mathbf{ldb}$ – Integer Input

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

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

6 Error Indicators and Warnings

7 Accuracy

8 Parallelism and Performance

9 Further Comments

10 Example