permute_matrix
Permutes the rows or columns of a matrix.
Synopsis
#include <imsls.h>
float *imsls_f_permute_matrix (int n_rows, int n_columns, float a[], int permutation[], Imsls_permute permute, …, 0)
The type double function is imsls_d_permute_matrix.
Required Arguments
int n_rows (Input)
Number of rows in the input matrix a.
int n_columns (Input)
Number of columns in the input matrix a.
float a[] (Input)
Matrix of size n_rows × n_columns to be permuted.
int permutation[] (Input)
Array of length n containing the permutation permutation[0], …, permutation[n-1] of the integers 0, …, n, where n = n_rows if the rows of a are to be permuted and n = n_columns if the columns of a are to be permuted.
Imsls_permute permute (Input)
Keyword of type Imsls_permute. Argument permute must be either IMSLS_PERMUTE_ROWS, if the rows of a are to be interchanged, or IMSLS_PERMUTE_COLUMNS, if the columns of a are to be interchanged.
Return Value
Array of size n_rows × n_columns containing the permuted input matrix a.
Synopsis with Optional Arguments
#include <imsls.h>
float *imsls_f_permute_matrix (int n_rows, int n_columns, float a[], int permutation[], Imsls_permute permute,
IMSLS_RETURN_USER, float permuted_result[],
0)
Optional Arguments
IMSLS_RETURN_USER, float permuted_result[] (Output)
User-allocated array of size n_rows × n_columns containing the result of the permutation.
Description
Function imsls_f_permute_matrix interchanges the rows or columns of a matrix using a permutation vector. The function permutes a column (row) at a time using function imsls_f_permute_vector. This process is continued until all the columns (rows) are permuted. On completion, let B = result and pi = permutation [i], then Bij = Apij for all i, j.
Example
This example permutes the columns of a matrix a.
#include <imsls.h>
int main()
{
float a[] = {3.0, 5.0, 1.0, 2.0, 4.0,
3.0, 5.0, 1.0, 2.0, 4.0,
3.0, 5.0, 1.0, 2.0, 4.0};
int permutation[] = {2, 3, 0, 4, 1};
float *output;
int n_rows = 3;
int n_columns = 5;
output = imsls_f_permute_matrix (n_rows, n_columns, a, permutation,
IMSLS_PERMUTE_COLUMNS,
0);
imsls_f_write_matrix ("permuted matrix", n_rows, n_columns, output,
IMSLS_ROW_NUMBER_ZERO,
IMSLS_COL_NUMBER_ZERO,
0);
}
Output
permuted matrix
0 1 2 3 4
0 1 2 3 4 5
1 1 2 3 4 5
2 1 2 3 4 5
