(S|D|C|Z)TRTRI¶

Single, double, single complex, and double complex TRTRI.

Description¶

Computes the inverse of a triangular matrix using a blocked algorithm.

If UPLO is ‘U’ then A is assumed to be upper triangular and the lower triangular part is not accessed.

If UPLO is ‘L’ then A is assumed to be lower triangular and the upper triangular part is not accessed.

If DIAG is ‘U’ then the diagonal of A is not accessed and is assumed to be 1. If Diag is ‘N’ then the diagonal of A is accessed.

LAPACK Interface¶

void strtri(const char *UPLO, const char *DIAG, const qml_long *N, float *A,
    const qml_long *LDA, qml_long *INFO);

void dtrtri(const char *UPLO, const char *DIAG, const qml_long *N, double *A,
    const qml_long *LDA, qml_long *INFO);

void ctrtri(const char *UPLO, const char *DIAG, const qml_long *N,
    qml_single_complex *A, const qml_long *LDA, qml_long *INFO);

void ztrtri(const char *UPLO, const char *DIAG, const qml_long *N,
    qml_double_complex *A, const qml_long *LDA, qml_long *INFO);

Arguments¶

UPLO	Specify whether to use ‘U’ upper triangular or ‘L’ lower triangular part of A
DIAG	Specify whether to assume ‘N’ non-unit triangular or ‘U’ unit triangular
N	Order of the matrix A
A	Matrix of size N x N, overwritten with inverse on exit
LDA	Leading dimension of A
INFO	0 on success, <0 on illegal arguments, >0 if singular