.TH "trtri" 3 "Wed Feb 7 2024 11:30:40" "Version 3.12.0" "LAPACK" \" -*- nroff -*- .ad l .nh .SH NAME trtri \- trtri: triangular inverse .SH SYNOPSIS .br .PP .SS "Functions" .in +1c .ti -1c .RI "subroutine \fBctrtri\fP (uplo, diag, n, a, lda, info)" .br .RI "\fBCTRTRI\fP " .ti -1c .RI "subroutine \fBdtrtri\fP (uplo, diag, n, a, lda, info)" .br .RI "\fBDTRTRI\fP " .ti -1c .RI "subroutine \fBstrtri\fP (uplo, diag, n, a, lda, info)" .br .RI "\fBSTRTRI\fP " .ti -1c .RI "subroutine \fBztrtri\fP (uplo, diag, n, a, lda, info)" .br .RI "\fBZTRTRI\fP " .in -1c .SH "Detailed Description" .PP .SH "Function Documentation" .PP .SS "subroutine ctrtri (character uplo, character diag, integer n, complex, dimension( lda, * ) a, integer lda, integer info)" .PP \fBCTRTRI\fP .PP \fBPurpose:\fP .RS 4 .PP .nf CTRTRI computes the inverse of a complex upper or lower triangular matrix A\&. This is the Level 3 BLAS version of the algorithm\&. .fi .PP .RE .PP \fBParameters\fP .RS 4 \fIUPLO\fP .PP .nf UPLO is CHARACTER*1 = 'U': A is upper triangular; = 'L': A is lower triangular\&. .fi .PP .br \fIDIAG\fP .PP .nf DIAG is CHARACTER*1 = 'N': A is non-unit triangular; = 'U': A is unit triangular\&. .fi .PP .br \fIN\fP .PP .nf N is INTEGER The order of the matrix A\&. N >= 0\&. .fi .PP .br \fIA\fP .PP .nf 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\&. .fi .PP .br \fILDA\fP .PP .nf LDA is INTEGER The leading dimension of the array A\&. LDA >= max(1,N)\&. .fi .PP .br \fIINFO\fP .PP .nf INFO is INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value > 0: if INFO = i, A(i,i) is exactly zero\&. The triangular matrix is singular and its inverse can not be computed\&. .fi .PP .RE .PP \fBAuthor\fP .RS 4 Univ\&. of Tennessee .PP Univ\&. of California Berkeley .PP Univ\&. of Colorado Denver .PP NAG Ltd\&. .RE .PP .SS "subroutine dtrtri (character uplo, character diag, integer n, double precision, dimension( lda, * ) a, integer lda, integer info)" .PP \fBDTRTRI\fP .PP \fBPurpose:\fP .RS 4 .PP .nf DTRTRI computes the inverse of a real upper or lower triangular matrix A\&. This is the Level 3 BLAS version of the algorithm\&. .fi .PP .RE .PP \fBParameters\fP .RS 4 \fIUPLO\fP .PP .nf UPLO is CHARACTER*1 = 'U': A is upper triangular; = 'L': A is lower triangular\&. .fi .PP .br \fIDIAG\fP .PP .nf DIAG is CHARACTER*1 = 'N': A is non-unit triangular; = 'U': A is unit triangular\&. .fi .PP .br \fIN\fP .PP .nf N is INTEGER The order of the matrix A\&. N >= 0\&. .fi .PP .br \fIA\fP .PP .nf 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\&. .fi .PP .br \fILDA\fP .PP .nf LDA is INTEGER The leading dimension of the array A\&. LDA >= max(1,N)\&. .fi .PP .br \fIINFO\fP .PP .nf INFO is INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value > 0: if INFO = i, A(i,i) is exactly zero\&. The triangular matrix is singular and its inverse can not be computed\&. .fi .PP .RE .PP \fBAuthor\fP .RS 4 Univ\&. of Tennessee .PP Univ\&. of California Berkeley .PP Univ\&. of Colorado Denver .PP NAG Ltd\&. .RE .PP .SS "subroutine strtri (character uplo, character diag, integer n, real, dimension( lda, * ) a, integer lda, integer info)" .PP \fBSTRTRI\fP .PP \fBPurpose:\fP .RS 4 .PP .nf STRTRI computes the inverse of a real upper or lower triangular matrix A\&. This is the Level 3 BLAS version of the algorithm\&. .fi .PP .RE .PP \fBParameters\fP .RS 4 \fIUPLO\fP .PP .nf UPLO is CHARACTER*1 = 'U': A is upper triangular; = 'L': A is lower triangular\&. .fi .PP .br \fIDIAG\fP .PP .nf DIAG is CHARACTER*1 = 'N': A is non-unit triangular; = 'U': A is unit triangular\&. .fi .PP .br \fIN\fP .PP .nf N is INTEGER The order of the matrix A\&. N >= 0\&. .fi .PP .br \fIA\fP .PP .nf 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\&. .fi .PP .br \fILDA\fP .PP .nf LDA is INTEGER The leading dimension of the array A\&. LDA >= max(1,N)\&. .fi .PP .br \fIINFO\fP .PP .nf INFO is INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value > 0: if INFO = i, A(i,i) is exactly zero\&. The triangular matrix is singular and its inverse can not be computed\&. .fi .PP .RE .PP \fBAuthor\fP .RS 4 Univ\&. of Tennessee .PP Univ\&. of California Berkeley .PP Univ\&. of Colorado Denver .PP NAG Ltd\&. .RE .PP .SS "subroutine ztrtri (character uplo, character diag, integer n, complex*16, dimension( lda, * ) a, integer lda, integer info)" .PP \fBZTRTRI\fP .PP \fBPurpose:\fP .RS 4 .PP .nf ZTRTRI computes the inverse of a complex upper or lower triangular matrix A\&. This is the Level 3 BLAS version of the algorithm\&. .fi .PP .RE .PP \fBParameters\fP .RS 4 \fIUPLO\fP .PP .nf UPLO is CHARACTER*1 = 'U': A is upper triangular; = 'L': A is lower triangular\&. .fi .PP .br \fIDIAG\fP .PP .nf DIAG is CHARACTER*1 = 'N': A is non-unit triangular; = 'U': A is unit triangular\&. .fi .PP .br \fIN\fP .PP .nf N is INTEGER The order of the matrix A\&. N >= 0\&. .fi .PP .br \fIA\fP .PP .nf 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\&. .fi .PP .br \fILDA\fP .PP .nf LDA is INTEGER The leading dimension of the array A\&. LDA >= max(1,N)\&. .fi .PP .br \fIINFO\fP .PP .nf INFO is INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value > 0: if INFO = i, A(i,i) is exactly zero\&. The triangular matrix is singular and its inverse can not be computed\&. .fi .PP .RE .PP \fBAuthor\fP .RS 4 Univ\&. of Tennessee .PP Univ\&. of California Berkeley .PP Univ\&. of Colorado Denver .PP NAG Ltd\&. .RE .PP .SH "Author" .PP Generated automatically by Doxygen for LAPACK from the source code\&.