permute_vector

Rearranges the elements of a vector as specified by a permutation.

Synopsis

#include <imsls.h>

float *imsls_f_permute_vector (int n_elements, float x[], int permutation[], Imsls_permute permute, .…, 0)

The type double function is imsls_d_permute_vector.

Required Arguments

int n_elements (Input)
Number of elements in the input vector x.

float x[] (Input)
Array of length n_elements to be permuted.

int permutation[] (Input)
Array of length n_elements containing the permutation.

Imsls_permute permute (Input)
Keyword of type Imsls_permute. Argument permute must be either IMSLS_FORWARD_PERMUTATION or IMSLS_BACKWARD_PERMUTATION. If IMSLS_FORWARD_PERMUTATION is specified, then a forward permutation is performed, i.e., x[permutation[i]] is moved to location i in the return vector. If IMSLS_BACKWARD_PERMUTATION is specified, then a backward permutation is performed, i.e., x[i] is moved to location permutation[i] in the return vector.

Return Value

An array of length n_elements containing the input vector x permuted.

Synopsis with Optional Arguments

#include <imsls.h>

float *imsls_f_permute_vector (int n_elements, float x[], int permutation[], Imsls_permute permute,
IMSLS_RETURN_USER, float permuted_result[],
0)

Optional Arguments

IMSLS_RETURN_USER, float permuted_result[](Output)
User-allocated array containing the result of the permutation.

Description

Function imsls_f_permute_vector rearranges the elements of a vector according to a permutation vector. The function can perform both forward and backward permutation.

Example

This example rearranges the vector x using permutation. A forward permutation is performed.

 

#include <imsls.h>

 

int main()

{

float x[] = {5.0, 6.0, 1.0, 4.0};

int permutation[] = {2, 0, 3, 1};

float *output;

int n_elements = 4;

 

output = imsls_f_permute_vector (n_elements, x, permutation,

IMSLS_FORWARD_PERMUTATION, 0);

 

imsls_f_write_matrix ("permuted result", 1, n_elements, output,

IMSLS_COL_NUMBER_ZERO, 0);

}

Output

 

permuted result

0 1 2 3

1 5 4 6