TPTTR - 5.2 English - 68552

AOCL API Guide (68552)

Document ID
68552
Release Date
2025-12-29
Version
5.2 English
template<typename T>
void tpttr(char *uplo, integer *n, T *ap, T *a, integer *lda, integer *info)#

TPTTR copies a triangular matrix from the standard

packed format (TP) to the standard full format (TR).

Purpose:

  TPTTR copies a triangular matrix A from standard packed format (TP)
  to standard full format (TR).
Parameters:
  • UPLO[in]

    UPLO is CHARACTER*1

    = ‘U’: A is upper triangular.

    = ‘L’: A is lower triangular.
  • N[in]

    N is INTEGER

    The order of the matrix A. N >= 0.

  • AP[in]

    AP is REAL array, dimension ( N*(N+1)/2),

    On entry, 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.

  • A[out]

    A is REAL array, dimension ( LDA, N)

    On exit, the triangular matrix A. If UPLO = ‘U’, the leading N-by-N upper triangular part of A contains the upper triangular part of the matrix A, and the strictly lower triangular part of A is not referenced. If UPLO = ‘L’, the leading N-by-N lower triangular part of A contains the lower triangular part of the matrix A, and the strictly upper triangular part of A is not referenced.

  • LDA[in]

    LDA is INTEGER

    The leading dimension of the array A. LDA >= fla_max(1,N).

  • INFO[out]

    INFO is INTEGER

    = 0: successful exit

    < 0: if INFO = -i, the i-th argument had an illegal value