NAG FL Interface
m01cbf (intvec_​sort)

1 Purpose

2 Specification

3 Description

4 References

5 Arguments

1: $\mathbf{iv}\left(\mathbf{m2}\right)$ – Integer array Input/Output

On entry: elements m1 to m2 of iv must contain integer values to be sorted.

On exit: these values are rearranged into sorted order.

2: $\mathbf{m1}$ – Integer Input

On entry: the index of the first element of iv to be sorted.

Constraint: $\mathbf{m1}>0$.

3: $\mathbf{m2}$ – Integer Input

On entry: the index of the last element of iv to be sorted.

Constraint: $\mathbf{m2}\ge \mathbf{m1}$.

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

On entry: if $\mathbf{order}=\text{'A'}$, the values will be sorted into ascending (i.e., nondecreasing) order.

If $\mathbf{order}=\text{'D'}$, into descending order.

Constraint: $\mathbf{order}=\text{'A'}$ or $\text{'D'}$.

5: $\mathbf{ifail}$ – Integer Input/Output

On entry: ifail must be set to $0$, $-1$ or $1$ to set behaviour on detection of an error; these values have no effect when no error is detected.

A value of $0$ causes the printing of an error message and program execution will be halted; otherwise program execution continues. A value of $-1$ means that an error message is printed while a value of $1$ means that it is not.

If halting is not appropriate, the value $-1$ or $1$ is recommended. If message printing is undesirable, then the value $1$ is recommended. Otherwise, the value $0$ is recommended. When the value $-\mathbf{1}$ or $\mathbf{1}$ is used it is essential to test the value of ifail on exit.

On exit: $\mathbf{ifail}=\mathbf{0}$ unless the routine detects an error or a warning has been flagged (see Section 6).

6 Error Indicators and Warnings

$\mathbf{ifail}=1$

On entry, $\mathbf{m1}=〈\mathit{\text{value}}〉$.
Constraint: $\mathbf{m1}\ge 1$.

On entry, $\mathbf{m1}=〈\mathit{\text{value}}〉$ and $\mathbf{m2}=〈\mathit{\text{value}}〉$.
Constraint: $\mathbf{m1}\le \mathbf{m2}$.

On entry, $\mathbf{m2}=〈\mathit{\text{value}}〉$.
Constraint: $\mathbf{m2}\ge 1$.

$\mathbf{ifail}=2$

On entry, order has an illegal value: $\mathbf{order}=〈\mathit{\text{value}}〉$.

$\mathbf{ifail}=-99$

An unexpected error has been triggered by this routine. Please contact NAG.

See Section 7 in the Introduction to the NAG Library FL Interface for further information.

$\mathbf{ifail}=-399$

Your licence key may have expired or may not have been installed correctly.

See Section 8 in the Introduction to the NAG Library FL Interface for further information.

$\mathbf{ifail}=-999$

Dynamic memory allocation failed.

See Section 9 in the Introduction to the NAG Library FL Interface for further information.

7 Accuracy

8 Parallelism and Performance

9 Further Comments

10 Example

10.1 Program Text

10.2 Program Data

10.3 Program Results