trti2 - trti2: triangular inverse, level 2

Generated automatically by Doxygen for LAPACK from the source code. Version 3.12.0 Sun Jul 20 2025 01:40:05 trti2(3)

subroutinectrti2(characteruplo,characterdiag,integern,complex,dimension(lda,*)a,integerlda,integerinfo)CTRTI2 computes the inverse of a triangular matrix (unblocked algorithm). Purpose: CTRTI2 computes the inverse of a complex upper or lower triangular matrix. This is the Level 2 BLAS version of the algorithm. ParametersUPLO UPLO is CHARACTER*1 Specifies whether the matrix A is upper or lower triangular. = 'U': Upper triangular = 'L': Lower triangular DIAG DIAG is CHARACTER*1 Specifies whether or not the matrix A is unit triangular. = 'N': Non-unit triangular = 'U': Unit triangular N N is INTEGER The order of the matrix A. N >= 0. A A is COMPLEX array, dimension (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. If DIAG = 'U', the diagonal elements of A are also not referenced and are assumed to be 1. On exit, the (triangular) inverse of the original matrix, in the same storage format. LDA LDA is INTEGER The leading dimension of the array A. LDA >= max(1,N). INFO INFO is INTEGER = 0: successful exit < 0: if INFO = -k, the k-th argument had an illegal value Author Univ. of Tennessee Univ. of California Berkeley Univ. of Colorado Denver NAG Ltd. subroutinedtrti2(characteruplo,characterdiag,integern,doubleprecision,dimension(lda,*)a,integerlda,integerinfo)DTRTI2 computes the inverse of a triangular matrix (unblocked algorithm). Purpose: DTRTI2 computes the inverse of a real upper or lower triangular matrix. This is the Level 2 BLAS version of the algorithm. ParametersUPLO UPLO is CHARACTER*1 Specifies whether the matrix A is upper or lower triangular. = 'U': Upper triangular = 'L': Lower triangular DIAG DIAG is CHARACTER*1 Specifies whether or not the matrix A is unit triangular. = 'N': Non-unit triangular = 'U': Unit triangular N N is INTEGER The order of the matrix A. N >= 0. A A is DOUBLE PRECISION array, dimension (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. If DIAG = 'U', the diagonal elements of A are also not referenced and are assumed to be 1. On exit, the (triangular) inverse of the original matrix, in the same storage format. LDA LDA is INTEGER The leading dimension of the array A. LDA >= max(1,N). INFO INFO is INTEGER = 0: successful exit < 0: if INFO = -k, the k-th argument had an illegal value Author Univ. of Tennessee Univ. of California Berkeley Univ. of Colorado Denver NAG Ltd. subroutinestrti2(characteruplo,characterdiag,integern,real,dimension(lda,*)a,integerlda,integerinfo)STRTI2 computes the inverse of a triangular matrix (unblocked algorithm). Purpose: STRTI2 computes the inverse of a real upper or lower triangular matrix. This is the Level 2 BLAS version of the algorithm. ParametersUPLO UPLO is CHARACTER*1 Specifies whether the matrix A is upper or lower triangular. = 'U': Upper triangular = 'L': Lower triangular DIAG DIAG is CHARACTER*1 Specifies whether or not the matrix A is unit triangular. = 'N': Non-unit triangular = 'U': Unit triangular N N is INTEGER The order of the matrix A. N >= 0. A A is REAL array, dimension (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. If DIAG = 'U', the diagonal elements of A are also not referenced and are assumed to be 1. On exit, the (triangular) inverse of the original matrix, in the same storage format. LDA LDA is INTEGER The leading dimension of the array A. LDA >= max(1,N). INFO INFO is INTEGER = 0: successful exit < 0: if INFO = -k, the k-th argument had an illegal value Author Univ. of Tennessee Univ. of California Berkeley Univ. of Colorado Denver NAG Ltd. subroutineztrti2(characteruplo,characterdiag,integern,complex*16,dimension(lda,*)a,integerlda,integerinfo)ZTRTI2 computes the inverse of a triangular matrix (unblocked algorithm). Purpose: ZTRTI2 computes the inverse of a complex upper or lower triangular matrix. This is the Level 2 BLAS version of the algorithm. ParametersUPLO UPLO is CHARACTER*1 Specifies whether the matrix A is upper or lower triangular. = 'U': Upper triangular = 'L': Lower triangular DIAG DIAG is CHARACTER*1 Specifies whether or not the matrix A is unit triangular. = 'N': Non-unit triangular = 'U': Unit triangular N N is INTEGER The order of the matrix A. N >= 0. A A is COMPLEX*16 array, dimension (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. If DIAG = 'U', the diagonal elements of A are also not referenced and are assumed to be 1. On exit, the (triangular) inverse of the original matrix, in the same storage format. LDA LDA is INTEGER The leading dimension of the array A. LDA >= max(1,N). INFO INFO is INTEGER = 0: successful exit < 0: if INFO = -k, the k-th argument had an illegal value Author Univ. of Tennessee Univ. of California Berkeley Univ. of Colorado Denver NAG Ltd.

trti2 - trti2: triangular inverse, level 2

Functions subroutine ctrti2 (uplo, diag, n, a, lda, info) CTRTI2 computes the inverse of a triangular matrix (unblocked algorithm). subroutine dtrti2 (uplo, diag, n, a, lda, info) DTRTI2 computes the inverse of a triangular matrix (unblocked algorithm). subroutine strti2 (uplo, diag, n, a, lda, info) STRTI2 computes the inverse of a triangular matrix (unblocked algorithm). subroutine ztrti2 (uplo, diag, n, a, lda, info) ZTRTI2 computes the inverse of a triangular matrix (unblocked algorithm).