ctrt023

!>
!> CTRT02 computes the residual for the computed solution to a
!> triangular system of linear equations op(A)*X = B, where A is a
!> triangular matrix. The test ratio is the maximum over
!>    norm(b - op(A)*x) / ( ||op(A)||_1 * norm(x) * EPS ),
!> where op(A) = A, A**T, or A**H, b is the column of B, x is the
!> solution vector, and EPS is the machine epsilon.
!> 

UPLO

!>          UPLO is CHARACTER*1
!>          Specifies whether the matrix A is upper or lower triangular.
!>          = 'U':  Upper triangular
!>          = 'L':  Lower triangular
!> 

TRANS

!>          TRANS is CHARACTER*1
!>          Specifies the operation applied to A.
!>          = 'N':  A    * X = B  (No transpose)
!>          = 'T':  A**T * X = B  (Transpose)
!>          = 'C':  A**H * X = B  (Conjugate transpose)
!> 

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.
!> 

NRHS

!>          NRHS is INTEGER
!>          The number of right hand sides, i.e., the number of columns
!>          of the matrices X and B.  NRHS >= 0.
!> 

A

!>          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.
!> 

LDA

!>          LDA is INTEGER
!>          The leading dimension of the array A.  LDA >= max(1,N).
!> 

X

!>          X is COMPLEX array, dimension (LDX,NRHS)
!>          The computed solution vectors for the system of linear
!>          equations.
!> 

LDX

!>          LDX is INTEGER
!>          The leading dimension of the array X.  LDX >= max(1,N).
!> 

B

!>          B is COMPLEX array, dimension (LDB,NRHS)
!>          The right hand side vectors for the system of linear
!>          equations.
!> 

LDB

!>          LDB is INTEGER
!>          The leading dimension of the array B.  LDB >= max(1,N).
!> 

WORK

!>          WORK is COMPLEX array, dimension (N)
!> 

RWORK

!>          RWORK is REAL array, dimension (N)
!> 

RESID

!>          RESID is REAL
!>          The maximum over the number of right hand sides of
!>          norm(op(A)*X - B) / ( norm(op(A)) * norm(X) * EPS ).
!> 

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.