176 lines
5.2 KiB
FortranFixed
176 lines
5.2 KiB
FortranFixed
SUBROUTINE CRQT01( M, N, A, AF, Q, R, LDA, TAU, WORK, LWORK,
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$ RWORK, RESULT )
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*
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* -- LAPACK test routine (version 3.1) --
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* Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd..
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* November 2006
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*
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* .. Scalar Arguments ..
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INTEGER LDA, LWORK, M, N
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* ..
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* .. Array Arguments ..
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REAL RESULT( * ), RWORK( * )
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COMPLEX A( LDA, * ), AF( LDA, * ), Q( LDA, * ),
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$ R( LDA, * ), TAU( * ), WORK( LWORK )
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* ..
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*
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* Purpose
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* =======
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*
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* CRQT01 tests CGERQF, which computes the RQ factorization of an m-by-n
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* matrix A, and partially tests CUNGRQ which forms the n-by-n
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* orthogonal matrix Q.
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*
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* CRQT01 compares R with A*Q', and checks that Q is orthogonal.
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*
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* Arguments
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* =========
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*
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* M (input) INTEGER
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* The number of rows of the matrix A. M >= 0.
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*
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* N (input) INTEGER
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* The number of columns of the matrix A. N >= 0.
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*
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* A (input) COMPLEX array, dimension (LDA,N)
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* The m-by-n matrix A.
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*
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* AF (output) COMPLEX array, dimension (LDA,N)
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* Details of the RQ factorization of A, as returned by CGERQF.
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* See CGERQF for further details.
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*
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* Q (output) COMPLEX array, dimension (LDA,N)
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* The n-by-n orthogonal matrix Q.
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*
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* R (workspace) COMPLEX array, dimension (LDA,max(M,N))
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*
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* LDA (input) INTEGER
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* The leading dimension of the arrays A, AF, Q and L.
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* LDA >= max(M,N).
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*
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* TAU (output) COMPLEX array, dimension (min(M,N))
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* The scalar factors of the elementary reflectors, as returned
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* by CGERQF.
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*
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* WORK (workspace) COMPLEX array, dimension (LWORK)
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*
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* LWORK (input) INTEGER
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* The dimension of the array WORK.
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*
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* RWORK (workspace) REAL array, dimension (max(M,N))
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*
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* RESULT (output) REAL array, dimension (2)
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* The test ratios:
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* RESULT(1) = norm( R - A*Q' ) / ( N * norm(A) * EPS )
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* RESULT(2) = norm( I - Q*Q' ) / ( N * EPS )
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*
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* =====================================================================
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*
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* .. Parameters ..
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REAL ZERO, ONE
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PARAMETER ( ZERO = 0.0E+0, ONE = 1.0E+0 )
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COMPLEX ROGUE
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PARAMETER ( ROGUE = ( -1.0E+10, -1.0E+10 ) )
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* ..
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* .. Local Scalars ..
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INTEGER INFO, MINMN
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REAL ANORM, EPS, RESID
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* ..
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* .. External Functions ..
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REAL CLANGE, CLANSY, SLAMCH
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EXTERNAL CLANGE, CLANSY, SLAMCH
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* ..
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* .. External Subroutines ..
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EXTERNAL CGEMM, CGERQF, CHERK, CLACPY, CLASET, CUNGRQ
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* ..
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* .. Intrinsic Functions ..
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INTRINSIC CMPLX, MAX, MIN, REAL
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* ..
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* .. Scalars in Common ..
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CHARACTER(32) SRNAMT
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* ..
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* .. Common blocks ..
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COMMON / SRNAMC / SRNAMT
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* ..
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* .. Executable Statements ..
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*
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MINMN = MIN( M, N )
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EPS = SLAMCH( 'Epsilon' )
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*
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* Copy the matrix A to the array AF.
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*
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CALL CLACPY( 'Full', M, N, A, LDA, AF, LDA )
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*
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* Factorize the matrix A in the array AF.
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*
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SRNAMT = 'CGERQF'
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CALL CGERQF( M, N, AF, LDA, TAU, WORK, LWORK, INFO )
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*
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* Copy details of Q
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*
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CALL CLASET( 'Full', N, N, ROGUE, ROGUE, Q, LDA )
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IF( M.LE.N ) THEN
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IF( M.GT.0 .AND. M.LT.N )
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$ CALL CLACPY( 'Full', M, N-M, AF, LDA, Q( N-M+1, 1 ), LDA )
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IF( M.GT.1 )
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$ CALL CLACPY( 'Lower', M-1, M-1, AF( 2, N-M+1 ), LDA,
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$ Q( N-M+2, N-M+1 ), LDA )
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ELSE
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IF( N.GT.1 )
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$ CALL CLACPY( 'Lower', N-1, N-1, AF( M-N+2, 1 ), LDA,
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$ Q( 2, 1 ), LDA )
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END IF
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*
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* Generate the n-by-n matrix Q
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*
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SRNAMT = 'CUNGRQ'
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CALL CUNGRQ( N, N, MINMN, Q, LDA, TAU, WORK, LWORK, INFO )
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*
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* Copy R
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*
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CALL CLASET( 'Full', M, N, CMPLX( ZERO ), CMPLX( ZERO ), R, LDA )
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IF( M.LE.N ) THEN
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IF( M.GT.0 )
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$ CALL CLACPY( 'Upper', M, M, AF( 1, N-M+1 ), LDA,
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$ R( 1, N-M+1 ), LDA )
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ELSE
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IF( M.GT.N .AND. N.GT.0 )
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$ CALL CLACPY( 'Full', M-N, N, AF, LDA, R, LDA )
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IF( N.GT.0 )
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$ CALL CLACPY( 'Upper', N, N, AF( M-N+1, 1 ), LDA,
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$ R( M-N+1, 1 ), LDA )
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END IF
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*
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* Compute R - A*Q'
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*
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CALL CGEMM( 'No transpose', 'Conjugate transpose', M, N, N,
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$ CMPLX( -ONE ), A, LDA, Q, LDA, CMPLX( ONE ), R, LDA )
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*
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* Compute norm( R - Q'*A ) / ( N * norm(A) * EPS ) .
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*
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ANORM = CLANGE( '1', M, N, A, LDA, RWORK )
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RESID = CLANGE( '1', M, N, R, LDA, RWORK )
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IF( ANORM.GT.ZERO ) THEN
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RESULT( 1 ) = ( ( RESID / REAL( MAX( 1, N ) ) ) / ANORM ) / EPS
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ELSE
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RESULT( 1 ) = ZERO
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END IF
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*
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* Compute I - Q*Q'
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*
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CALL CLASET( 'Full', N, N, CMPLX( ZERO ), CMPLX( ONE ), R, LDA )
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CALL CHERK( 'Upper', 'No transpose', N, N, -ONE, Q, LDA, ONE, R,
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$ LDA )
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*
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* Compute norm( I - Q*Q' ) / ( N * EPS ) .
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*
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RESID = CLANSY( '1', 'Upper', N, R, LDA, RWORK )
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*
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RESULT( 2 ) = ( RESID / REAL( MAX( 1, N ) ) ) / EPS
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*
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RETURN
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*
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* End of CRQT01
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*
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END
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