1: $iperm (m2)$ – int64int32nag_int array: Elements m1 to m2 of iperm must be set to values which are supposed to be a permutation of the integers m1 to m2. If they are a valid permutation, the function exits with $ifail = 0$ .
2: $m1$ – int64int32nag_int scalar: The range of elements used in the array iperm and the range of values in the permutation, as specified under iperm.

Constraint: $0 < m1 \leq m2$ .

Optional Input Parameters

1: $m2$ – int64int32nag_int scalar: Default: the dimension of the array iperm.
The range of elements used in the array iperm and the range of values in the permutation, as specified under iperm.

Constraint: $0 < m1 \leq m2$ .

Output Parameters

1: $iperm (m2)$ – int64int32nag_int array: Used as internal workpsace prior to being restored and hence is unchanged.
2: $ifail$ – int64int32nag_int scalar: $ifail = 0$ unless the function detects an error (see Error Indicators and Warnings).

Error Indicators and Warnings

Errors or warnings detected by the function:

$ifail = 1$

On entry,	$m2 < 1$ ,
or	$m1 < 1$ ,
or	$m1 > m2$ .

$ifail = 2$: Elements m1 to m2 of iperm contain a value outside the range m1 to m2.

$ifail = 3$: Elements m1 to m2 of iperm contain a repeated value.

$ifail = - 99$: An unexpected error has been triggered by this routine. Please contact NAG.

$ifail = - 399$: Your licence key may have expired or may not have been installed correctly.

$ifail = - 999$: Dynamic memory allocation failed.

ifail = 2

3

, elements m1 to m2 of iperm do not contain a permutation of the integers m1 to m2.

Accuracy

Not applicable.

Further Comments

None.

Example

This example reads in a vector of real numbers, and a vector of ranks; it calls nag_sort_permute_check (m01zb) to check the validity of the ranks before calling nag_sort_realvec_rank_rearrange (m01ea) to rearrange the real numbers into the specified order.

Open in the MATLAB editor: m01zb_example

function m01zb_example


fprintf('m01zb example results\n\n');

rv    = [      5.3  4.6  7.8 1.7 5.3  9.9 3.2 4.3  7.8 4.5 1.2 7.6];
iperm = [int64(7) 6   10   2   8   12   3   4   11   5   1   9];

m1 = int64(1);
[iperm, ifail] = m01zb(iperm, m1);

[rv, iperm, ifail] = m01ea(rv, m1, iperm);

disp('Numbers in rank order');
fprintf('%5.1f%5.1f%5.1f%5.1f%5.1f%5.1f\n',rv);

m01zb example results

Numbers in rank order
  1.2  1.7  3.2  4.3  4.5  4.6
  5.3  5.3  7.6  7.8  7.8  9.9

PDF version (NAG web site, 64-bit version, 64-bit version)

Chapter Contents

Chapter Introduction

NAG Toolbox