POTRS - 5.2 English - 68552

AOCL API Guide (68552)

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

POTRS solves a system of linear equations A*X = B.

Purpose:

  POTRS solves a system of linear equations A*X = B with a symmetric
  positive definite matrix A using the Cholesky factorization
  A = U**T*U or A = L*L**T computed by SPOTRF.
Parameters:
  • UPLO[in]

    UPLO is CHARACTER*1

    = ‘U’: Upper triangle of A is stored;

    = ‘L’: Lower triangle of A is stored.
  • N[in]

    N is INTEGER

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

  • NRHS[in]

    NRHS is INTEGER

    The number of right hand sides, i.e., the number of columns of the matrix B. NRHS >= 0.

  • A[in]

    A is REAL array, dimension (LDA,N)

    The triangular factor U or L from the Cholesky factorization A = U**T*U or A = L*L**T, as computed by SPOTRF.

  • LDA[in]

    LDA is INTEGER

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

  • B[inout]

    B is REAL array, dimension (LDB,NRHS)

    On entry, the right hand side matrix B. On exit, the solution matrix X.

  • LDB[in]

    LDB is INTEGER

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

  • INFO[out]

    INFO is INTEGER

    = 0: successful exit

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