TESTING/LIN/zgtt02.f(3) Library Functions Manual TESTING/LIN/zgtt02.f(3)

TESTING/LIN/zgtt02.f


subroutine zgtt02 (trans, n, nrhs, dl, d, du, x, ldx, b, ldb, resid)
ZGTT02

ZGTT02

Purpose:

!>
!> ZGTT02 computes the residual for the solution to a tridiagonal
!> system of equations:
!>    RESID = norm(B - op(A)*X) / (norm(op(A)) * norm(X) * EPS),
!> where EPS is the machine epsilon.
!> 

Parameters

TRANS
!>          TRANS is CHARACTER
!>          Specifies the form of the residual.
!>          = 'N':  B - A    * X  (No transpose)
!>          = 'T':  B - A**T * X  (Transpose)
!>          = 'C':  B - A**H * X  (Conjugate transpose)
!> 

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 B and X.  NRHS >= 0.
!> 

DL

!>          DL is COMPLEX*16 array, dimension (N-1)
!>          The (n-1) sub-diagonal elements of A.
!> 

D

!>          D is COMPLEX*16 array, dimension (N)
!>          The diagonal elements of A.
!> 

DU

!>          DU is COMPLEX*16 array, dimension (N-1)
!>          The (n-1) super-diagonal elements of A.
!> 

X

!>          X is COMPLEX*16 array, dimension (LDX,NRHS)
!>          The computed solution vectors X.
!> 

LDX

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

B

!>          B is COMPLEX*16 array, dimension (LDB,NRHS)
!>          On entry, the right hand side vectors for the system of
!>          linear equations.
!>          On exit, B is overwritten with the difference B - op(A)*X.
!> 

LDB

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

RESID

!>          RESID is DOUBLE PRECISION
!>          norm(B - op(A)*X) / (norm(op(A)) * norm(X) * EPS)
!> 

Author

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Definition at line 122 of file zgtt02.f.

Generated automatically by Doxygen for LAPACK from the source code.

Version 3.12.0 LAPACK