Annotation of rpl/lapack/lapack/zlacrm.f, revision 1.18
1.11 bertrand 1: *> \brief \b ZLACRM multiplies a complex matrix by a square real matrix.
1.8 bertrand 2: *
3: * =========== DOCUMENTATION ===========
4: *
1.15 bertrand 5: * Online html documentation available at
6: * http://www.netlib.org/lapack/explore-html/
1.8 bertrand 7: *
8: *> \htmlonly
1.15 bertrand 9: *> Download ZLACRM + dependencies
10: *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/zlacrm.f">
11: *> [TGZ]</a>
12: *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/zlacrm.f">
13: *> [ZIP]</a>
14: *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/zlacrm.f">
1.8 bertrand 15: *> [TXT]</a>
1.15 bertrand 16: *> \endhtmlonly
1.8 bertrand 17: *
18: * Definition:
19: * ===========
20: *
21: * SUBROUTINE ZLACRM( M, N, A, LDA, B, LDB, C, LDC, RWORK )
1.15 bertrand 22: *
1.8 bertrand 23: * .. Scalar Arguments ..
24: * INTEGER LDA, LDB, LDC, M, N
25: * ..
26: * .. Array Arguments ..
27: * DOUBLE PRECISION B( LDB, * ), RWORK( * )
28: * COMPLEX*16 A( LDA, * ), C( LDC, * )
29: * ..
1.15 bertrand 30: *
1.8 bertrand 31: *
32: *> \par Purpose:
33: * =============
34: *>
35: *> \verbatim
36: *>
37: *> ZLACRM performs a very simple matrix-matrix multiplication:
38: *> C := A * B,
39: *> where A is M by N and complex; B is N by N and real;
40: *> C is M by N and complex.
41: *> \endverbatim
42: *
43: * Arguments:
44: * ==========
45: *
46: *> \param[in] M
47: *> \verbatim
48: *> M is INTEGER
49: *> The number of rows of the matrix A and of the matrix C.
50: *> M >= 0.
51: *> \endverbatim
52: *>
53: *> \param[in] N
54: *> \verbatim
55: *> N is INTEGER
56: *> The number of columns and rows of the matrix B and
57: *> the number of columns of the matrix C.
58: *> N >= 0.
59: *> \endverbatim
60: *>
61: *> \param[in] A
62: *> \verbatim
63: *> A is COMPLEX*16 array, dimension (LDA, N)
1.15 bertrand 64: *> On entry, A contains the M by N matrix A.
1.8 bertrand 65: *> \endverbatim
66: *>
67: *> \param[in] LDA
68: *> \verbatim
69: *> LDA is INTEGER
70: *> The leading dimension of the array A. LDA >=max(1,M).
71: *> \endverbatim
72: *>
73: *> \param[in] B
74: *> \verbatim
75: *> B is DOUBLE PRECISION array, dimension (LDB, N)
1.15 bertrand 76: *> On entry, B contains the N by N matrix B.
1.8 bertrand 77: *> \endverbatim
78: *>
79: *> \param[in] LDB
80: *> \verbatim
81: *> LDB is INTEGER
82: *> The leading dimension of the array B. LDB >=max(1,N).
83: *> \endverbatim
84: *>
1.15 bertrand 85: *> \param[out] C
1.8 bertrand 86: *> \verbatim
87: *> C is COMPLEX*16 array, dimension (LDC, N)
1.15 bertrand 88: *> On exit, C contains the M by N matrix C.
1.8 bertrand 89: *> \endverbatim
90: *>
91: *> \param[in] LDC
92: *> \verbatim
93: *> LDC is INTEGER
94: *> The leading dimension of the array C. LDC >=max(1,N).
95: *> \endverbatim
96: *>
97: *> \param[out] RWORK
98: *> \verbatim
99: *> RWORK is DOUBLE PRECISION array, dimension (2*M*N)
100: *> \endverbatim
101: *
102: * Authors:
103: * ========
104: *
1.15 bertrand 105: *> \author Univ. of Tennessee
106: *> \author Univ. of California Berkeley
107: *> \author Univ. of Colorado Denver
108: *> \author NAG Ltd.
1.8 bertrand 109: *
110: *> \ingroup complex16OTHERauxiliary
111: *
112: * =====================================================================
1.1 bertrand 113: SUBROUTINE ZLACRM( M, N, A, LDA, B, LDB, C, LDC, RWORK )
114: *
1.18 ! bertrand 115: * -- LAPACK auxiliary routine --
1.1 bertrand 116: * -- LAPACK is a software package provided by Univ. of Tennessee, --
117: * -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
118: *
119: * .. Scalar Arguments ..
120: INTEGER LDA, LDB, LDC, M, N
121: * ..
122: * .. Array Arguments ..
123: DOUBLE PRECISION B( LDB, * ), RWORK( * )
124: COMPLEX*16 A( LDA, * ), C( LDC, * )
125: * ..
126: *
127: * =====================================================================
128: *
129: * .. Parameters ..
130: DOUBLE PRECISION ONE, ZERO
131: PARAMETER ( ONE = 1.0D0, ZERO = 0.0D0 )
132: * ..
133: * .. Local Scalars ..
134: INTEGER I, J, L
135: * ..
136: * .. Intrinsic Functions ..
137: INTRINSIC DBLE, DCMPLX, DIMAG
138: * ..
139: * .. External Subroutines ..
140: EXTERNAL DGEMM
141: * ..
142: * .. Executable Statements ..
143: *
144: * Quick return if possible.
145: *
146: IF( ( M.EQ.0 ) .OR. ( N.EQ.0 ) )
147: $ RETURN
148: *
149: DO 20 J = 1, N
150: DO 10 I = 1, M
151: RWORK( ( J-1 )*M+I ) = DBLE( A( I, J ) )
152: 10 CONTINUE
153: 20 CONTINUE
154: *
155: L = M*N + 1
156: CALL DGEMM( 'N', 'N', M, N, N, ONE, RWORK, M, B, LDB, ZERO,
157: $ RWORK( L ), M )
158: DO 40 J = 1, N
159: DO 30 I = 1, M
160: C( I, J ) = RWORK( L+( J-1 )*M+I-1 )
161: 30 CONTINUE
162: 40 CONTINUE
163: *
164: DO 60 J = 1, N
165: DO 50 I = 1, M
166: RWORK( ( J-1 )*M+I ) = DIMAG( A( I, J ) )
167: 50 CONTINUE
168: 60 CONTINUE
169: CALL DGEMM( 'N', 'N', M, N, N, ONE, RWORK, M, B, LDB, ZERO,
170: $ RWORK( L ), M )
171: DO 80 J = 1, N
172: DO 70 I = 1, M
173: C( I, J ) = DCMPLX( DBLE( C( I, J ) ),
174: $ RWORK( L+( J-1 )*M+I-1 ) )
175: 70 CONTINUE
176: 80 CONTINUE
177: *
178: RETURN
179: *
180: * End of ZLACRM
181: *
182: END
CVSweb interface <joel.bertrand@systella.fr>