TESTING/LIN/ztbt02.f(3)

NAME
TESTING/LIN/ztbt02.f

SYNOPSIS

  Functions/Subroutines
subroutine ztbt02 (uplo, trans, diag, n, kd, nrhs, ab, ldab, x, ldx, b, ldb, work, rwork, resid)
ZTBT02

Function/Subroutine Documentation

  subroutine ztbt02 (character uplo, character trans, character diag, integer n, integer kd, integer nrhs, complex*16, dimension( ldab, * ) ab, integer ldab, complex*16, dimension( ldx, * ) x, integer ldx, complex*16, dimension( ldb, * ) b, integer ldb, complex*16, dimension( * ) work, double precision, dimension( * ) rwork, double precision resid)

ZTBT02

Purpose:

    !>
    !> ZTBT02 computes the residual for the computed solution to a
    !> triangular system of linear equations op(A)*X = B, when A is a
    !> triangular band 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.
    !>

    KD

    !>          KD is INTEGER
    !>          The number of superdiagonals or subdiagonals of the
    !>          triangular band matrix A.  KD >= 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.
    !>

    AB

    !>          AB is COMPLEX*16 array, dimension (LDA,N)
    !>          The upper or lower triangular band matrix A, stored in the
    !>          first kd+1 rows of the array. The j-th column of A is stored
    !>          in the j-th column of the array AB as follows:
    !>          if UPLO = 'U', AB(kd+1+i-j,j) = A(i,j) for max(1,j-kd)<=i<=j;
    !>          if UPLO = 'L', AB(1+i-j,j)    = A(i,j) for j<=i<=min(n,j+kd).
    !>

    LDAB

    !>          LDAB is INTEGER
    !>          The leading dimension of the array AB.  LDAB >= max(1,KD+1).
    !>

    X

    !>          X is COMPLEX*16 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*16 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*16 array, dimension (N)
    !>

    RWORK

    !>          RWORK is DOUBLE PRECISION array, dimension (N)
    !>

    RESID

    !>          RESID is DOUBLE PRECISION
    !>          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 157 of file ztbt02.f.

Author

Generated automatically by Doxygen for LAPACK from the source code.