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LAPACK
3.4.1
LAPACK: Linear Algebra PACKage
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00001 *> \brief \b CQRT13 00002 * 00003 * =========== DOCUMENTATION =========== 00004 * 00005 * Online html documentation available at 00006 * http://www.netlib.org/lapack/explore-html/ 00007 * 00008 * Definition: 00009 * =========== 00010 * 00011 * SUBROUTINE CQRT13( SCALE, M, N, A, LDA, NORMA, ISEED ) 00012 * 00013 * .. Scalar Arguments .. 00014 * INTEGER LDA, M, N, SCALE 00015 * REAL NORMA 00016 * .. 00017 * .. Array Arguments .. 00018 * INTEGER ISEED( 4 ) 00019 * COMPLEX A( LDA, * ) 00020 * .. 00021 * 00022 * 00023 *> \par Purpose: 00024 * ============= 00025 *> 00026 *> \verbatim 00027 *> 00028 *> CQRT13 generates a full-rank matrix that may be scaled to have large 00029 *> or small norm. 00030 *> \endverbatim 00031 * 00032 * Arguments: 00033 * ========== 00034 * 00035 *> \param[in] SCALE 00036 *> \verbatim 00037 *> SCALE is INTEGER 00038 *> SCALE = 1: normally scaled matrix 00039 *> SCALE = 2: matrix scaled up 00040 *> SCALE = 3: matrix scaled down 00041 *> \endverbatim 00042 *> 00043 *> \param[in] M 00044 *> \verbatim 00045 *> M is INTEGER 00046 *> The number of rows of the matrix A. 00047 *> \endverbatim 00048 *> 00049 *> \param[in] N 00050 *> \verbatim 00051 *> N is INTEGER 00052 *> The number of columns of A. 00053 *> \endverbatim 00054 *> 00055 *> \param[out] A 00056 *> \verbatim 00057 *> A is COMPLEX array, dimension (LDA,N) 00058 *> The M-by-N matrix A. 00059 *> \endverbatim 00060 *> 00061 *> \param[in] LDA 00062 *> \verbatim 00063 *> LDA is INTEGER 00064 *> The leading dimension of the array A. 00065 *> \endverbatim 00066 *> 00067 *> \param[out] NORMA 00068 *> \verbatim 00069 *> NORMA is REAL 00070 *> The one-norm of A. 00071 *> \endverbatim 00072 *> 00073 *> \param[in,out] ISEED 00074 *> \verbatim 00075 *> ISEED is integer array, dimension (4) 00076 *> Seed for random number generator 00077 *> \endverbatim 00078 * 00079 * Authors: 00080 * ======== 00081 * 00082 *> \author Univ. of Tennessee 00083 *> \author Univ. of California Berkeley 00084 *> \author Univ. of Colorado Denver 00085 *> \author NAG Ltd. 00086 * 00087 *> \date November 2011 00088 * 00089 *> \ingroup complex_lin 00090 * 00091 * ===================================================================== 00092 SUBROUTINE CQRT13( SCALE, M, N, A, LDA, NORMA, ISEED ) 00093 * 00094 * -- LAPACK test routine (version 3.4.0) -- 00095 * -- LAPACK is a software package provided by Univ. of Tennessee, -- 00096 * -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- 00097 * November 2011 00098 * 00099 * .. Scalar Arguments .. 00100 INTEGER LDA, M, N, SCALE 00101 REAL NORMA 00102 * .. 00103 * .. Array Arguments .. 00104 INTEGER ISEED( 4 ) 00105 COMPLEX A( LDA, * ) 00106 * .. 00107 * 00108 * ===================================================================== 00109 * 00110 * .. Parameters .. 00111 REAL ONE 00112 PARAMETER ( ONE = 1.0E0 ) 00113 * .. 00114 * .. Local Scalars .. 00115 INTEGER INFO, J 00116 REAL BIGNUM, SMLNUM 00117 * .. 00118 * .. External Functions .. 00119 REAL CLANGE, SCASUM, SLAMCH 00120 EXTERNAL CLANGE, SCASUM, SLAMCH 00121 * .. 00122 * .. External Subroutines .. 00123 EXTERNAL CLARNV, CLASCL, SLABAD 00124 * .. 00125 * .. Intrinsic Functions .. 00126 INTRINSIC CMPLX, REAL, SIGN 00127 * .. 00128 * .. Local Arrays .. 00129 REAL DUMMY( 1 ) 00130 * .. 00131 * .. Executable Statements .. 00132 * 00133 IF( M.LE.0 .OR. N.LE.0 ) 00134 $ RETURN 00135 * 00136 * benign matrix 00137 * 00138 DO 10 J = 1, N 00139 CALL CLARNV( 2, ISEED, M, A( 1, J ) ) 00140 IF( J.LE.M ) THEN 00141 A( J, J ) = A( J, J ) + CMPLX( SIGN( SCASUM( M, A( 1, J ), 00142 $ 1 ), REAL( A( J, J ) ) ) ) 00143 END IF 00144 10 CONTINUE 00145 * 00146 * scaled versions 00147 * 00148 IF( SCALE.NE.1 ) THEN 00149 NORMA = CLANGE( 'Max', M, N, A, LDA, DUMMY ) 00150 SMLNUM = SLAMCH( 'Safe minimum' ) 00151 BIGNUM = ONE / SMLNUM 00152 CALL SLABAD( SMLNUM, BIGNUM ) 00153 SMLNUM = SMLNUM / SLAMCH( 'Epsilon' ) 00154 BIGNUM = ONE / SMLNUM 00155 * 00156 IF( SCALE.EQ.2 ) THEN 00157 * 00158 * matrix scaled up 00159 * 00160 CALL CLASCL( 'General', 0, 0, NORMA, BIGNUM, M, N, A, LDA, 00161 $ INFO ) 00162 ELSE IF( SCALE.EQ.3 ) THEN 00163 * 00164 * matrix scaled down 00165 * 00166 CALL CLASCL( 'General', 0, 0, NORMA, SMLNUM, M, N, A, LDA, 00167 $ INFO ) 00168 END IF 00169 END IF 00170 * 00171 NORMA = CLANGE( 'One-norm', M, N, A, LDA, DUMMY ) 00172 RETURN 00173 * 00174 * End of CQRT13 00175 * 00176 END