TPLQT2 - 5.2 English - 68552

AOCL API Guide (68552)

Document ID
68552
Release Date
2025-12-29
Version
5.2 English
template<typename T>
void tplqt2(integer *m, integer *n, integer *l, T *a, integer *lda, T *b, integer *ldb, T *t, integer *ldt, integer *info)#

TPLQT2 computes a LQ factorization of a real or complex “triangular-pentagonal” matrix.

Purpose:

   TPLQT2 computes a LQ a factorization of a real "triangular-pentagonal"
   matrix C, which is composed of a triangular block A and pentagonal block B,
   using the compact WY representation for Q.
Parameters:
  • M[in]

    M is INTEGER

    The total number of rows of the matrix B. M >= 0.

  • N[in]

    N is INTEGER

    The number of columns of the matrix B, and the order of the triangular matrix A. N >= 0.

  • L[in]

    L is INTEGER

    The number of rows of the lower trapezoidal part of B. MIN(M,N) >= L >= 0. See Further Details.

  • A[inout]

    A is REAL array, dimension (LDA,M)

    On entry, the lower triangular M-by-M matrix A.

    On exit, the elements on and below the diagonal of the array contain the lower triangular matrix L.
  • LDA[in]

    LDA is INTEGER

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

  • B[inout]

    B is REAL array, dimension (LDB,N)

    On entry, the pentagonal M-by-N matrix B. The first N-L columns are rectangular, and the last L columns are lower trapezoidal.

    On exit, B contains the pentagonal matrix V. See Further Details.
  • LDB[in]

    LDB is INTEGER

    The leading dimension of the array B. LDB >= fla_max(1,M).

  • T[out]

    T is REAL array, dimension (LDT,M)

    The N-by-N upper triangular factor T of the block reflector. See Further Details.

  • LDT[in]

    LDT is INTEGER

    The leading dimension of the array T. LDT >= fla_max(1,M)

  • INFO[out]

    INFO is INTEGER

    = 0: successful exit

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