table of contents
/home/abuild/rpmbuild/BUILD/lapack-3.12.0/TESTING/LIN/dtrt06.f(3) | Library Functions Manual | /home/abuild/rpmbuild/BUILD/lapack-3.12.0/TESTING/LIN/dtrt06.f(3) |
NAME¶
/home/abuild/rpmbuild/BUILD/lapack-3.12.0/TESTING/LIN/dtrt06.f
SYNOPSIS¶
Functions/Subroutines¶
subroutine DTRT06 (rcond, rcondc, uplo, diag, n, a, lda,
work, rat)
DTRT06
Function/Subroutine Documentation¶
subroutine DTRT06 (double precision rcond, double precision rcondc, character uplo, character diag, integer n, double precision, dimension( lda, * ) a, integer lda, double precision, dimension( * ) work, double precision rat)¶
DTRT06
Purpose:
!> !> DTRT06 computes a test ratio comparing RCOND (the reciprocal !> condition number of a triangular matrix A) and RCONDC, the estimate !> computed by DTRCON. Information about the triangular matrix A is !> used if one estimate is zero and the other is non-zero to decide if !> underflow in the estimate is justified. !>
Parameters
RCOND
!> RCOND is DOUBLE PRECISION !> The estimate of the reciprocal condition number obtained by !> forming the explicit inverse of the matrix A and computing !> RCOND = 1/( norm(A) * norm(inv(A)) ). !>
RCONDC
!> RCONDC is DOUBLE PRECISION !> The estimate of the reciprocal condition number computed by !> DTRCON. !>
UPLO
!> UPLO is CHARACTER !> Specifies whether the matrix A is upper or lower triangular. !> = 'U': Upper triangular !> = 'L': Lower triangular !>
DIAG
!> DIAG is CHARACTER !> 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) !> 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. !>
LDA
!> LDA is INTEGER !> The leading dimension of the array A. LDA >= max(1,N). !>
WORK
!> WORK is DOUBLE PRECISION array, dimension (N) !>
RAT
!> RAT is DOUBLE PRECISION !> The test ratio. If both RCOND and RCONDC are nonzero, !> RAT = MAX( RCOND, RCONDC )/MIN( RCOND, RCONDC ) - 1. !> If RAT = 0, the two estimates are exactly the same. !>
Author
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Definition at line 119 of file dtrt06.f.
Author¶
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Version 3.12.0 | LAPACK |