.TH "trcon" 3 "Version 3.12.0" "LAPACK" \" -*- nroff -*- .ad l .nh .SH NAME trcon \- trcon: condition number estimate .SH SYNOPSIS .br .PP .SS "Functions" .in +1c .ti -1c .RI "subroutine \fBctrcon\fP (norm, uplo, diag, n, a, lda, rcond, work, rwork, info)" .br .RI "\fBCTRCON\fP " .ti -1c .RI "subroutine \fBdtrcon\fP (norm, uplo, diag, n, a, lda, rcond, work, iwork, info)" .br .RI "\fBDTRCON\fP " .ti -1c .RI "subroutine \fBstrcon\fP (norm, uplo, diag, n, a, lda, rcond, work, iwork, info)" .br .RI "\fBSTRCON\fP " .ti -1c .RI "subroutine \fBztrcon\fP (norm, uplo, diag, n, a, lda, rcond, work, rwork, info)" .br .RI "\fBZTRCON\fP " .in -1c .SH "Detailed Description" .PP .SH "Function Documentation" .PP .SS "subroutine ctrcon (character norm, character uplo, character diag, integer n, complex, dimension( lda, * ) a, integer lda, real rcond, complex, dimension( * ) work, real, dimension( * ) rwork, integer info)" .PP \fBCTRCON\fP .PP \fBPurpose:\fP .RS 4 .PP .nf !> !> CTRCON estimates the reciprocal of the condition number of a !> triangular matrix A, in either the 1-norm or the infinity-norm\&. !> !> The norm of A is computed and an estimate is obtained for !> norm(inv(A)), then the reciprocal of the condition number is !> computed as !> RCOND = 1 / ( norm(A) * norm(inv(A)) )\&. !> .fi .PP .RE .PP \fBParameters\fP .RS 4 \fINORM\fP .PP .nf !> NORM is CHARACTER*1 !> Specifies whether the 1-norm condition number or the !> infinity-norm condition number is required: !> = '1' or 'O': 1-norm; !> = 'I': Infinity-norm\&. !> .fi .PP .br \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) !> 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\&. !> .fi .PP .br \fILDA\fP .PP .nf !> LDA is INTEGER !> The leading dimension of the array A\&. LDA >= max(1,N)\&. !> .fi .PP .br \fIRCOND\fP .PP .nf !> RCOND is REAL !> The reciprocal of the condition number of the matrix A, !> computed as RCOND = 1/(norm(A) * norm(inv(A)))\&. !> .fi .PP .br \fIWORK\fP .PP .nf !> WORK is COMPLEX array, dimension (2*N) !> .fi .PP .br \fIRWORK\fP .PP .nf !> RWORK is REAL array, dimension (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 !> .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 .PP Definition at line \fB135\fP of file \fBctrcon\&.f\fP\&. .SS "subroutine dtrcon (character norm, character uplo, character diag, integer n, double precision, dimension( lda, * ) a, integer lda, double precision rcond, double precision, dimension( * ) work, integer, dimension( * ) iwork, integer info)" .PP \fBDTRCON\fP .PP \fBPurpose:\fP .RS 4 .PP .nf !> !> DTRCON estimates the reciprocal of the condition number of a !> triangular matrix A, in either the 1-norm or the infinity-norm\&. !> !> The norm of A is computed and an estimate is obtained for !> norm(inv(A)), then the reciprocal of the condition number is !> computed as !> RCOND = 1 / ( norm(A) * norm(inv(A)) )\&. !> .fi .PP .RE .PP \fBParameters\fP .RS 4 \fINORM\fP .PP .nf !> NORM is CHARACTER*1 !> Specifies whether the 1-norm condition number or the !> infinity-norm condition number is required: !> = '1' or 'O': 1-norm; !> = 'I': Infinity-norm\&. !> .fi .PP .br \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) !> 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\&. !> .fi .PP .br \fILDA\fP .PP .nf !> LDA is INTEGER !> The leading dimension of the array A\&. LDA >= max(1,N)\&. !> .fi .PP .br \fIRCOND\fP .PP .nf !> RCOND is DOUBLE PRECISION !> The reciprocal of the condition number of the matrix A, !> computed as RCOND = 1/(norm(A) * norm(inv(A)))\&. !> .fi .PP .br \fIWORK\fP .PP .nf !> WORK is DOUBLE PRECISION array, dimension (3*N) !> .fi .PP .br \fIIWORK\fP .PP .nf !> IWORK is INTEGER array, dimension (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 !> .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 .PP Definition at line \fB135\fP of file \fBdtrcon\&.f\fP\&. .SS "subroutine strcon (character norm, character uplo, character diag, integer n, real, dimension( lda, * ) a, integer lda, real rcond, real, dimension( * ) work, integer, dimension( * ) iwork, integer info)" .PP \fBSTRCON\fP .PP \fBPurpose:\fP .RS 4 .PP .nf !> !> STRCON estimates the reciprocal of the condition number of a !> triangular matrix A, in either the 1-norm or the infinity-norm\&. !> !> The norm of A is computed and an estimate is obtained for !> norm(inv(A)), then the reciprocal of the condition number is !> computed as !> RCOND = 1 / ( norm(A) * norm(inv(A)) )\&. !> .fi .PP .RE .PP \fBParameters\fP .RS 4 \fINORM\fP .PP .nf !> NORM is CHARACTER*1 !> Specifies whether the 1-norm condition number or the !> infinity-norm condition number is required: !> = '1' or 'O': 1-norm; !> = 'I': Infinity-norm\&. !> .fi .PP .br \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) !> 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\&. !> .fi .PP .br \fILDA\fP .PP .nf !> LDA is INTEGER !> The leading dimension of the array A\&. LDA >= max(1,N)\&. !> .fi .PP .br \fIRCOND\fP .PP .nf !> RCOND is REAL !> The reciprocal of the condition number of the matrix A, !> computed as RCOND = 1/(norm(A) * norm(inv(A)))\&. !> .fi .PP .br \fIWORK\fP .PP .nf !> WORK is REAL array, dimension (3*N) !> .fi .PP .br \fIIWORK\fP .PP .nf !> IWORK is INTEGER array, dimension (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 !> .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 .PP Definition at line \fB135\fP of file \fBstrcon\&.f\fP\&. .SS "subroutine ztrcon (character norm, character uplo, character diag, integer n, complex*16, dimension( lda, * ) a, integer lda, double precision rcond, complex*16, dimension( * ) work, double precision, dimension( * ) rwork, integer info)" .PP \fBZTRCON\fP .PP \fBPurpose:\fP .RS 4 .PP .nf !> !> ZTRCON estimates the reciprocal of the condition number of a !> triangular matrix A, in either the 1-norm or the infinity-norm\&. !> !> The norm of A is computed and an estimate is obtained for !> norm(inv(A)), then the reciprocal of the condition number is !> computed as !> RCOND = 1 / ( norm(A) * norm(inv(A)) )\&. !> .fi .PP .RE .PP \fBParameters\fP .RS 4 \fINORM\fP .PP .nf !> NORM is CHARACTER*1 !> Specifies whether the 1-norm condition number or the !> infinity-norm condition number is required: !> = '1' or 'O': 1-norm; !> = 'I': Infinity-norm\&. !> .fi .PP .br \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) !> 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\&. !> .fi .PP .br \fILDA\fP .PP .nf !> LDA is INTEGER !> The leading dimension of the array A\&. LDA >= max(1,N)\&. !> .fi .PP .br \fIRCOND\fP .PP .nf !> RCOND is DOUBLE PRECISION !> The reciprocal of the condition number of the matrix A, !> computed as RCOND = 1/(norm(A) * norm(inv(A)))\&. !> .fi .PP .br \fIWORK\fP .PP .nf !> WORK is COMPLEX*16 array, dimension (2*N) !> .fi .PP .br \fIRWORK\fP .PP .nf !> RWORK is DOUBLE PRECISION array, dimension (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 !> .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 .PP Definition at line \fB135\fP of file \fBztrcon\&.f\fP\&. .SH "Author" .PP Generated automatically by Doxygen for LAPACK from the source code\&.