TESTING/LIN/ctrt02.f(3)

NAME
TESTING/LIN/ctrt02.f

SYNOPSIS

  Functions/Subroutines
subroutine ctrt02 (uplo, trans, diag, n, nrhs, a, lda, x, ldx, b, ldb, work, rwork, resid)
CTRT02

Function/Subroutine Documentation

  subroutine ctrt02 (character uplo, character trans, character diag, integer n, integer nrhs, complex, dimension( lda, * ) a, integer lda, complex, dimension( ldx, * ) x, integer ldx, complex, dimension( ldb, * ) b, integer ldb, complex, dimension( * ) work, real, dimension( * ) rwork, real resid)

CTRT02

Purpose:

     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.

Parameters
    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 ).

Author
    Univ. of Tennessee

    Univ. of California Berkeley

    Univ. of Colorado Denver

    NAG Ltd.

Definition at line 153 of file ctrt02.f.

Author

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