naginterfaces.library.blas.dgeap

naginterfaces.library.blas.dgeap(side, trans, perm, k, b)[source]

dgeap permutes the rows or columns of a real rectangular matrix using an int array of permutations.

For full information please refer to the NAG Library document for f06qj

https://www.nag.com/numeric/nl/nagdoc_28.7/flhtml/f06/f06qjf.html

Parameters
sidestr, length 1

Specifies the operation to be performed.

and

.

and

.

and

.

and

.

transstr, length 1

Specifies the operation to be performed.

and

.

and

.

and

.

and

.

permint, array-like, shape

The indices which define the interchanges in the representation of . It is usual to have , but this is not necessary.

kint

, the number of columns of if , or the number of rows of if .

bfloat, array-like, shape

Note: the required extent for this argument in dimension 1 is determined as follows: if : ; if : ; otherwise: .

Note: the required extent for this argument in dimension 2 is determined as follows: if : ; if : ; otherwise: .

The original matrix ; is if , or if .

Returns
bfloat, ndarray, shape

The permuted matrix .

Raises
NagValueError
(errno )

On entry, error in parameter .

Constraint: or .

(errno )

On entry, error in parameter .

Constraint: or .

(errno )

On entry, error in parameter .

Constraint: .

(errno )

On entry, error in parameter .

Constraint: .

(errno )

On entry, error in parameter .

Constraint: .

Notes

No equivalent traditional C interface for this routine exists in the NAG Library.

dgeap performs one of the permutation operations

where is a real matrix, and is a permutation matrix.

is represented in the form

where is the permutation matrix that interchanges items and ; that is, is the unit matrix with rows and columns and interchanged. If , .

Let denote the number of rows of if , or the number of columns of if : the function does not require to be passed as an argument, but assumes that , for .

This function requires the indices to be supplied in an int array; dgeapr() performs the same operation with the indices supplied in a float array.