?trttp

Developer Reference for Intel® oneAPI Math Kernel Library for Fortran

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ID 766686

Date 10/15/2026

Version

Public

?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. Specifies the order of the matrix A. The value of n must be at least zero.

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 . On exit, the upper or lower triangular matrix A , packed columnwise in a linear array. (see Matrix Storage Schemes )

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.

Return Values

No return value, info is an Output Parameter.

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Developer Reference for Intel® oneAPI Math Kernel Library for Fortran

?trttp

Syntax

Include Files

Description

Input Parameters

Output Parameters

Return Values