1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184
|
*> \brief \b CRZT01
*
* =========== DOCUMENTATION ===========
*
* Online html documentation available at
* http://www.netlib.org/lapack/explore-html/
*
* Definition:
* ===========
*
* REAL FUNCTION CRZT01( M, N, A, AF, LDA, TAU, WORK,
* LWORK )
*
* .. Scalar Arguments ..
* INTEGER LDA, LWORK, M, N
* ..
* .. Array Arguments ..
* COMPLEX A( LDA, * ), AF( LDA, * ), TAU( * ),
* $ WORK( LWORK )
* ..
*
*
*> \par Purpose:
* =============
*>
*> \verbatim
*>
*> CRZT01 returns
*> || A - R*Q || / ( M * eps * ||A|| )
*> for an upper trapezoidal A that was factored with CTZRZF.
*> \endverbatim
*
* Arguments:
* ==========
*
*> \param[in] M
*> \verbatim
*> M is INTEGER
*> The number of rows of the matrices A and AF.
*> \endverbatim
*>
*> \param[in] N
*> \verbatim
*> N is INTEGER
*> The number of columns of the matrices A and AF.
*> \endverbatim
*>
*> \param[in] A
*> \verbatim
*> A is COMPLEX array, dimension (LDA,N)
*> The original upper trapezoidal M by N matrix A.
*> \endverbatim
*>
*> \param[in] AF
*> \verbatim
*> AF is COMPLEX array, dimension (LDA,N)
*> The output of CTZRZF for input matrix A.
*> The lower triangle is not referenced.
*> \endverbatim
*>
*> \param[in] LDA
*> \verbatim
*> LDA is INTEGER
*> The leading dimension of the arrays A and AF.
*> \endverbatim
*>
*> \param[in] TAU
*> \verbatim
*> TAU is COMPLEX array, dimension (M)
*> Details of the Householder transformations as returned by
*> CTZRZF.
*> \endverbatim
*>
*> \param[out] WORK
*> \verbatim
*> WORK is COMPLEX array, dimension (LWORK)
*> \endverbatim
*>
*> \param[in] LWORK
*> \verbatim
*> LWORK is INTEGER
*> The length of the array WORK. LWORK >= m*n + m.
*> \endverbatim
*
* Authors:
* ========
*
*> \author Univ. of Tennessee
*> \author Univ. of California Berkeley
*> \author Univ. of Colorado Denver
*> \author NAG Ltd.
*
*> \date November 2011
*
*> \ingroup complex_lin
*
* =====================================================================
REAL FUNCTION CRZT01( M, N, A, AF, LDA, TAU, WORK,
$ LWORK )
*
* -- LAPACK test routine (version 3.4.0) --
* -- LAPACK is a software package provided by Univ. of Tennessee, --
* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
* November 2011
*
* .. Scalar Arguments ..
INTEGER LDA, LWORK, M, N
* ..
* .. Array Arguments ..
COMPLEX A( LDA, * ), AF( LDA, * ), TAU( * ),
$ WORK( LWORK )
* ..
*
* =====================================================================
*
* .. Parameters ..
REAL ZERO, ONE
PARAMETER ( ZERO = 0.0E0, ONE = 1.0E0 )
* ..
* .. Local Scalars ..
INTEGER I, INFO, J
REAL NORMA
* ..
* .. Local Arrays ..
REAL RWORK( 1 )
* ..
* .. External Functions ..
REAL CLANGE, SLAMCH
EXTERNAL CLANGE, SLAMCH
* ..
* .. External Subroutines ..
EXTERNAL CAXPY, CLASET, CUNMRZ, XERBLA
* ..
* .. Intrinsic Functions ..
INTRINSIC CMPLX, MAX, REAL
* ..
* .. Executable Statements ..
*
CRZT01 = ZERO
*
IF( LWORK.LT.M*N+M ) THEN
CALL XERBLA( 'CRZT01', 8 )
RETURN
END IF
*
* Quick return if possible
*
IF( M.LE.0 .OR. N.LE.0 )
$ RETURN
*
NORMA = CLANGE( 'One-norm', M, N, A, LDA, RWORK )
*
* Copy upper triangle R
*
CALL CLASET( 'Full', M, N, CMPLX( ZERO ), CMPLX( ZERO ), WORK, M )
DO 20 J = 1, M
DO 10 I = 1, J
WORK( ( J-1 )*M+I ) = AF( I, J )
10 CONTINUE
20 CONTINUE
*
* R = R * P(1) * ... *P(m)
*
CALL CUNMRZ( 'Right', 'No tranpose', M, N, M, N-M, AF, LDA, TAU,
$ WORK, M, WORK( M*N+1 ), LWORK-M*N, INFO )
*
* R = R - A
*
DO 30 I = 1, N
CALL CAXPY( M, CMPLX( -ONE ), A( 1, I ), 1,
$ WORK( ( I-1 )*M+1 ), 1 )
30 CONTINUE
*
CRZT01 = CLANGE( 'One-norm', M, N, WORK, M, RWORK )
*
CRZT01 = CRZT01 / ( SLAMCH( 'Epsilon' )*REAL( MAX( M, N ) ) )
IF( NORMA.NE.ZERO )
$ CRZT01 = CRZT01 / NORMA
*
RETURN
*
* End of CRZT01
*
END
|