LAPACK 3.11.0 LAPACK: Linear Algebra PACKage
Searching...
No Matches
zlacrm.f
Go to the documentation of this file.
1*> \brief \b ZLACRM multiplies a complex matrix by a square real matrix.
2*
3* =========== DOCUMENTATION ===========
4*
5* Online html documentation available at
6* http://www.netlib.org/lapack/explore-html/
7*
8*> \htmlonly
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">
15*> [TXT]</a>
16*> \endhtmlonly
17*
18* Definition:
19* ===========
20*
21* SUBROUTINE ZLACRM( M, N, A, LDA, B, LDB, C, LDC, RWORK )
22*
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* ..
30*
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)
64*> On entry, A contains the M by N matrix A.
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)
76*> On entry, B contains the N by N matrix B.
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*>
85*> \param[out] C
86*> \verbatim
87*> C is COMPLEX*16 array, dimension (LDC, N)
88*> On exit, C contains the M by N matrix C.
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*
105*> \author Univ. of Tennessee
106*> \author Univ. of California Berkeley
107*> \author Univ. of Colorado Denver
108*> \author NAG Ltd.
109*
110*> \ingroup complex16OTHERauxiliary
111*
112* =====================================================================
113 SUBROUTINE zlacrm( M, N, A, LDA, B, LDB, C, LDC, RWORK )
114*
115* -- LAPACK auxiliary routine --
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
subroutine zlacrm(M, N, A, LDA, B, LDB, C, LDC, RWORK)
ZLACRM multiplies a complex matrix by a square real matrix.
Definition: zlacrm.f:114
subroutine dgemm(TRANSA, TRANSB, M, N, K, ALPHA, A, LDA, B, LDB, BETA, C, LDC)
DGEMM
Definition: dgemm.f:187