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/home/abuild/rpmbuild/BUILD/lapack-3.12.0/TESTING/EIG/dget51.f(3) Library Functions Manual /home/abuild/rpmbuild/BUILD/lapack-3.12.0/TESTING/EIG/dget51.f(3)

NAME

/home/abuild/rpmbuild/BUILD/lapack-3.12.0/TESTING/EIG/dget51.f

SYNOPSIS

Functions/Subroutines


subroutine DGET51 (itype, n, a, lda, b, ldb, u, ldu, v, ldv, work, result)
DGET51

Function/Subroutine Documentation

subroutine DGET51 (integer itype, integer n, double precision, dimension( lda, * ) a, integer lda, double precision, dimension( ldb, * ) b, integer ldb, double precision, dimension( ldu, * ) u, integer ldu, double precision, dimension( ldv, * ) v, integer ldv, double precision, dimension( * ) work, double precision result)

DGET51

Purpose:

!>
!>      DGET51  generally checks a decomposition of the form
!>
!>              A = U B V'
!>
!>      where ' means transpose and U and V are orthogonal.
!>
!>      Specifically, if ITYPE=1
!>
!>              RESULT = | A - U B V' | / ( |A| n ulp )
!>
!>      If ITYPE=2, then:
!>
!>              RESULT = | A - B | / ( |A| n ulp )
!>
!>      If ITYPE=3, then:
!>
!>              RESULT = | I - UU' | / ( n ulp )
!>

Parameters

ITYPE 

!>          ITYPE is INTEGER
!>          Specifies the type of tests to be performed.
!>          =1: RESULT = | A - U B V' | / ( |A| n ulp )
!>          =2: RESULT = | A - B | / ( |A| n ulp )
!>          =3: RESULT = | I - UU' | / ( n ulp )
!>

N

!>          N is INTEGER
!>          The size of the matrix.  If it is zero, DGET51 does nothing.
!>          It must be at least zero.
!>

A

!>          A is DOUBLE PRECISION array, dimension (LDA, N)
!>          The original (unfactored) matrix.
!>

LDA

!>          LDA is INTEGER
!>          The leading dimension of A.  It must be at least 1
!>          and at least N.
!>

B

!>          B is DOUBLE PRECISION array, dimension (LDB, N)
!>          The factored matrix.
!>

LDB

!>          LDB is INTEGER
!>          The leading dimension of B.  It must be at least 1
!>          and at least N.
!>

U

!>          U is DOUBLE PRECISION array, dimension (LDU, N)
!>          The orthogonal matrix on the left-hand side in the
!>          decomposition.
!>          Not referenced if ITYPE=2
!>

LDU

!>          LDU is INTEGER
!>          The leading dimension of U.  LDU must be at least N and
!>          at least 1.
!>

V

!>          V is DOUBLE PRECISION array, dimension (LDV, N)
!>          The orthogonal matrix on the left-hand side in the
!>          decomposition.
!>          Not referenced if ITYPE=2
!>

LDV

!>          LDV is INTEGER
!>          The leading dimension of V.  LDV must be at least N and
!>          at least 1.
!>

WORK

!>          WORK is DOUBLE PRECISION array, dimension (2*N**2)
!>

RESULT

!>          RESULT is DOUBLE PRECISION
!>          The values computed by the test specified by ITYPE.  The
!>          value is currently limited to 1/ulp, to avoid overflow.
!>          Errors are flagged by RESULT=10/ulp.
!>

Author

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Definition at line 147 of file dget51.f.

Author

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Version 3.12.0 LAPACK