Developer Reference for Intel® oneAPI Math Kernel Library for Fortran

ID 766686
Date 6/24/2024
Public

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?trttp

Copies a triangular matrix from the standard full format (TR) to the standard packed format (TP) .

Syntax

call strttp( uplo, n, a, lda, ap, info )

call dtrttp( uplo, n, a, lda, ap, info )

call ctrttp( uplo, n, a, lda, ap, info )

call ztrttp( uplo, n, a, lda, ap, info )

Include Files

  • mkl.fi

Description

The routine copies a triangular matrix A from the standard full format to the standard packed format.

Input Parameters

uplo

CHARACTER*1.

Specifies whether A is upper or lower triangular:

= 'U': A is upper triangular,

= 'L': A is lower triangular.

n

INTEGER. The order of the matrix A, n 0.

a

REAL for strttp,

DOUBLE PRECISION for dtrttp,

COMPLEX for ctrttp,

DOUBLE COMPLEX for ztrttp.

Array, size (lda, n).

On entry, the triangular matrix A. If uplo = 'U', the leading n-by-n upper triangular part of the array a contains the upper triangular matrix, and the strictly lower triangular part of a is not referenced. If uplo = 'L', the leading n-by-n lower triangular part of the array a contains the lower triangular matrix, and the strictly upper triangular part of a is not referenced.

lda

INTEGER. The leading dimension of the array a. lda max(1,n).

Output Parameters

ap

REAL for strttp,

DOUBLE PRECISION for dtrttp,

COMPLEX for ctrttp,

DOUBLE COMPLEX for ztrttp.

Array, size at least max (1, n*(n+1)/2).

On exit, the upper or lower triangular matrix A, packed columnwise in a linear array. The j-th column of A is stored in the array ap as follows:

if uplo = 'U', ap(i + (j-1)*j/2) = A(i,j) for 1 i j,

if uplo = 'L', ap(i + (j-1)*(2n-j)/2) = A(i,j) for j i n.

info

INTEGER. If info = 0, the execution is successful.

If info < 0, the i-th parameter had an illegal value.

If info = -1011, memory allocation error occurred.