![]() |
LAPACK
3.4.1
LAPACK: Linear Algebra PACKage
|
00001 *> \brief \b CUNMR2 00002 * 00003 * =========== DOCUMENTATION =========== 00004 * 00005 * Online html documentation available at 00006 * http://www.netlib.org/lapack/explore-html/ 00007 * 00008 *> \htmlonly 00009 *> Download CUNMR2 + dependencies 00010 *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/cunmr2.f"> 00011 *> [TGZ]</a> 00012 *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/cunmr2.f"> 00013 *> [ZIP]</a> 00014 *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/cunmr2.f"> 00015 *> [TXT]</a> 00016 *> \endhtmlonly 00017 * 00018 * Definition: 00019 * =========== 00020 * 00021 * SUBROUTINE CUNMR2( SIDE, TRANS, M, N, K, A, LDA, TAU, C, LDC, 00022 * WORK, INFO ) 00023 * 00024 * .. Scalar Arguments .. 00025 * CHARACTER SIDE, TRANS 00026 * INTEGER INFO, K, LDA, LDC, M, N 00027 * .. 00028 * .. Array Arguments .. 00029 * COMPLEX A( LDA, * ), C( LDC, * ), TAU( * ), WORK( * ) 00030 * .. 00031 * 00032 * 00033 *> \par Purpose: 00034 * ============= 00035 *> 00036 *> \verbatim 00037 *> 00038 *> CUNMR2 overwrites the general complex m-by-n matrix C with 00039 *> 00040 *> Q * C if SIDE = 'L' and TRANS = 'N', or 00041 *> 00042 *> Q**H* C if SIDE = 'L' and TRANS = 'C', or 00043 *> 00044 *> C * Q if SIDE = 'R' and TRANS = 'N', or 00045 *> 00046 *> C * Q**H if SIDE = 'R' and TRANS = 'C', 00047 *> 00048 *> where Q is a complex unitary matrix defined as the product of k 00049 *> elementary reflectors 00050 *> 00051 *> Q = H(1)**H H(2)**H . . . H(k)**H 00052 *> 00053 *> as returned by CGERQF. Q is of order m if SIDE = 'L' and of order n 00054 *> if SIDE = 'R'. 00055 *> \endverbatim 00056 * 00057 * Arguments: 00058 * ========== 00059 * 00060 *> \param[in] SIDE 00061 *> \verbatim 00062 *> SIDE is CHARACTER*1 00063 *> = 'L': apply Q or Q**H from the Left 00064 *> = 'R': apply Q or Q**H from the Right 00065 *> \endverbatim 00066 *> 00067 *> \param[in] TRANS 00068 *> \verbatim 00069 *> TRANS is CHARACTER*1 00070 *> = 'N': apply Q (No transpose) 00071 *> = 'C': apply Q**H (Conjugate transpose) 00072 *> \endverbatim 00073 *> 00074 *> \param[in] M 00075 *> \verbatim 00076 *> M is INTEGER 00077 *> The number of rows of the matrix C. M >= 0. 00078 *> \endverbatim 00079 *> 00080 *> \param[in] N 00081 *> \verbatim 00082 *> N is INTEGER 00083 *> The number of columns of the matrix C. N >= 0. 00084 *> \endverbatim 00085 *> 00086 *> \param[in] K 00087 *> \verbatim 00088 *> K is INTEGER 00089 *> The number of elementary reflectors whose product defines 00090 *> the matrix Q. 00091 *> If SIDE = 'L', M >= K >= 0; 00092 *> if SIDE = 'R', N >= K >= 0. 00093 *> \endverbatim 00094 *> 00095 *> \param[in] A 00096 *> \verbatim 00097 *> A is COMPLEX array, dimension 00098 *> (LDA,M) if SIDE = 'L', 00099 *> (LDA,N) if SIDE = 'R' 00100 *> The i-th row must contain the vector which defines the 00101 *> elementary reflector H(i), for i = 1,2,...,k, as returned by 00102 *> CGERQF in the last k rows of its array argument A. 00103 *> A is modified by the routine but restored on exit. 00104 *> \endverbatim 00105 *> 00106 *> \param[in] LDA 00107 *> \verbatim 00108 *> LDA is INTEGER 00109 *> The leading dimension of the array A. LDA >= max(1,K). 00110 *> \endverbatim 00111 *> 00112 *> \param[in] TAU 00113 *> \verbatim 00114 *> TAU is COMPLEX array, dimension (K) 00115 *> TAU(i) must contain the scalar factor of the elementary 00116 *> reflector H(i), as returned by CGERQF. 00117 *> \endverbatim 00118 *> 00119 *> \param[in,out] C 00120 *> \verbatim 00121 *> C is COMPLEX array, dimension (LDC,N) 00122 *> On entry, the m-by-n matrix C. 00123 *> On exit, C is overwritten by Q*C or Q**H*C or C*Q**H or C*Q. 00124 *> \endverbatim 00125 *> 00126 *> \param[in] LDC 00127 *> \verbatim 00128 *> LDC is INTEGER 00129 *> The leading dimension of the array C. LDC >= max(1,M). 00130 *> \endverbatim 00131 *> 00132 *> \param[out] WORK 00133 *> \verbatim 00134 *> WORK is COMPLEX array, dimension 00135 *> (N) if SIDE = 'L', 00136 *> (M) if SIDE = 'R' 00137 *> \endverbatim 00138 *> 00139 *> \param[out] INFO 00140 *> \verbatim 00141 *> INFO is INTEGER 00142 *> = 0: successful exit 00143 *> < 0: if INFO = -i, the i-th argument had an illegal value 00144 *> \endverbatim 00145 * 00146 * Authors: 00147 * ======== 00148 * 00149 *> \author Univ. of Tennessee 00150 *> \author Univ. of California Berkeley 00151 *> \author Univ. of Colorado Denver 00152 *> \author NAG Ltd. 00153 * 00154 *> \date November 2011 00155 * 00156 *> \ingroup complexOTHERcomputational 00157 * 00158 * ===================================================================== 00159 SUBROUTINE CUNMR2( SIDE, TRANS, M, N, K, A, LDA, TAU, C, LDC, 00160 $ WORK, INFO ) 00161 * 00162 * -- LAPACK computational routine (version 3.4.0) -- 00163 * -- LAPACK is a software package provided by Univ. of Tennessee, -- 00164 * -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- 00165 * November 2011 00166 * 00167 * .. Scalar Arguments .. 00168 CHARACTER SIDE, TRANS 00169 INTEGER INFO, K, LDA, LDC, M, N 00170 * .. 00171 * .. Array Arguments .. 00172 COMPLEX A( LDA, * ), C( LDC, * ), TAU( * ), WORK( * ) 00173 * .. 00174 * 00175 * ===================================================================== 00176 * 00177 * .. Parameters .. 00178 COMPLEX ONE 00179 PARAMETER ( ONE = ( 1.0E+0, 0.0E+0 ) ) 00180 * .. 00181 * .. Local Scalars .. 00182 LOGICAL LEFT, NOTRAN 00183 INTEGER I, I1, I2, I3, MI, NI, NQ 00184 COMPLEX AII, TAUI 00185 * .. 00186 * .. External Functions .. 00187 LOGICAL LSAME 00188 EXTERNAL LSAME 00189 * .. 00190 * .. External Subroutines .. 00191 EXTERNAL CLACGV, CLARF, XERBLA 00192 * .. 00193 * .. Intrinsic Functions .. 00194 INTRINSIC CONJG, MAX 00195 * .. 00196 * .. Executable Statements .. 00197 * 00198 * Test the input arguments 00199 * 00200 INFO = 0 00201 LEFT = LSAME( SIDE, 'L' ) 00202 NOTRAN = LSAME( TRANS, 'N' ) 00203 * 00204 * NQ is the order of Q 00205 * 00206 IF( LEFT ) THEN 00207 NQ = M 00208 ELSE 00209 NQ = N 00210 END IF 00211 IF( .NOT.LEFT .AND. .NOT.LSAME( SIDE, 'R' ) ) THEN 00212 INFO = -1 00213 ELSE IF( .NOT.NOTRAN .AND. .NOT.LSAME( TRANS, 'C' ) ) THEN 00214 INFO = -2 00215 ELSE IF( M.LT.0 ) THEN 00216 INFO = -3 00217 ELSE IF( N.LT.0 ) THEN 00218 INFO = -4 00219 ELSE IF( K.LT.0 .OR. K.GT.NQ ) THEN 00220 INFO = -5 00221 ELSE IF( LDA.LT.MAX( 1, K ) ) THEN 00222 INFO = -7 00223 ELSE IF( LDC.LT.MAX( 1, M ) ) THEN 00224 INFO = -10 00225 END IF 00226 IF( INFO.NE.0 ) THEN 00227 CALL XERBLA( 'CUNMR2', -INFO ) 00228 RETURN 00229 END IF 00230 * 00231 * Quick return if possible 00232 * 00233 IF( M.EQ.0 .OR. N.EQ.0 .OR. K.EQ.0 ) 00234 $ RETURN 00235 * 00236 IF( ( LEFT .AND. .NOT.NOTRAN .OR. .NOT.LEFT .AND. NOTRAN ) ) THEN 00237 I1 = 1 00238 I2 = K 00239 I3 = 1 00240 ELSE 00241 I1 = K 00242 I2 = 1 00243 I3 = -1 00244 END IF 00245 * 00246 IF( LEFT ) THEN 00247 NI = N 00248 ELSE 00249 MI = M 00250 END IF 00251 * 00252 DO 10 I = I1, I2, I3 00253 IF( LEFT ) THEN 00254 * 00255 * H(i) or H(i)**H is applied to C(1:m-k+i,1:n) 00256 * 00257 MI = M - K + I 00258 ELSE 00259 * 00260 * H(i) or H(i)**H is applied to C(1:m,1:n-k+i) 00261 * 00262 NI = N - K + I 00263 END IF 00264 * 00265 * Apply H(i) or H(i)**H 00266 * 00267 IF( NOTRAN ) THEN 00268 TAUI = CONJG( TAU( I ) ) 00269 ELSE 00270 TAUI = TAU( I ) 00271 END IF 00272 CALL CLACGV( NQ-K+I-1, A( I, 1 ), LDA ) 00273 AII = A( I, NQ-K+I ) 00274 A( I, NQ-K+I ) = ONE 00275 CALL CLARF( SIDE, MI, NI, A( I, 1 ), LDA, TAUI, C, LDC, WORK ) 00276 A( I, NQ-K+I ) = AII 00277 CALL CLACGV( NQ-K+I-1, A( I, 1 ), LDA ) 00278 10 CONTINUE 00279 RETURN 00280 * 00281 * End of CUNMR2 00282 * 00283 END