LAPACK 3.12.0 LAPACK: Linear Algebra PACKage
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zlag2c.f
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1*> \brief \b ZLAG2C converts a complex double precision matrix to a complex single precision 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/zlag2c.f">
11*> [TGZ]</a>
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13*> [ZIP]</a>
14*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/zlag2c.f">
15*> [TXT]</a>
16*> \endhtmlonly
17*
18* Definition:
19* ===========
20*
21* SUBROUTINE ZLAG2C( M, N, A, LDA, SA, LDSA, INFO )
22*
23* .. Scalar Arguments ..
24* INTEGER INFO, LDA, LDSA, M, N
25* ..
26* .. Array Arguments ..
27* COMPLEX SA( LDSA, * )
28* COMPLEX*16 A( LDA, * )
29* ..
30*
31*
32*> \par Purpose:
33* =============
34*>
35*> \verbatim
36*>
37*> ZLAG2C converts a COMPLEX*16 matrix, SA, to a COMPLEX matrix, A.
38*>
39*> RMAX is the overflow for the SINGLE PRECISION arithmetic
40*> ZLAG2C checks that all the entries of A are between -RMAX and
41*> RMAX. If not the conversion is aborted and a flag is raised.
42*>
43*> This is an auxiliary routine so there is no argument checking.
44*> \endverbatim
45*
46* Arguments:
47* ==========
48*
49*> \param[in] M
50*> \verbatim
51*> M is INTEGER
52*> The number of lines of the matrix A. M >= 0.
53*> \endverbatim
54*>
55*> \param[in] N
56*> \verbatim
57*> N is INTEGER
58*> The number of columns of the matrix A. N >= 0.
59*> \endverbatim
60*>
61*> \param[in] A
62*> \verbatim
63*> A is COMPLEX*16 array, dimension (LDA,N)
64*> On entry, the M-by-N coefficient 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[out] SA
74*> \verbatim
75*> SA is COMPLEX array, dimension (LDSA,N)
76*> On exit, if INFO=0, the M-by-N coefficient matrix SA; if
77*> INFO>0, the content of SA is unspecified.
78*> \endverbatim
79*>
80*> \param[in] LDSA
81*> \verbatim
82*> LDSA is INTEGER
83*> The leading dimension of the array SA. LDSA >= max(1,M).
84*> \endverbatim
85*>
86*> \param[out] INFO
87*> \verbatim
88*> INFO is INTEGER
89*> = 0: successful exit.
90*> = 1: an entry of the matrix A is greater than the SINGLE
91*> PRECISION overflow threshold, in this case, the content
92*> of SA in exit is unspecified.
93*> \endverbatim
94*
95* Authors:
96* ========
97*
98*> \author Univ. of Tennessee
99*> \author Univ. of California Berkeley
100*> \author Univ. of Colorado Denver
101*> \author NAG Ltd.
102*
103*> \ingroup _lag2_
104*
105* =====================================================================
106 SUBROUTINE zlag2c( M, N, A, LDA, SA, LDSA, INFO )
107*
108* -- LAPACK auxiliary routine --
109* -- LAPACK is a software package provided by Univ. of Tennessee, --
110* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
111*
112* .. Scalar Arguments ..
113 INTEGER INFO, LDA, LDSA, M, N
114* ..
115* .. Array Arguments ..
116 COMPLEX SA( LDSA, * )
117 COMPLEX*16 A( LDA, * )
118* ..
119*
120* =====================================================================
121*
122* .. Local Scalars ..
123 INTEGER I, J
124 DOUBLE PRECISION RMAX
125* ..
126* .. Intrinsic Functions ..
127 INTRINSIC dble, dimag, cmplx
128* ..
129* .. External Functions ..
130 REAL SLAMCH
131 EXTERNAL slamch
132* ..
133* .. Executable Statements ..
134*
135 rmax = slamch( 'O' )
136 DO 20 j = 1, n
137 DO 10 i = 1, m
138 IF( ( dble( a( i, j ) ).LT.-rmax ) .OR.
139 \$ ( dble( a( i, j ) ).GT.rmax ) .OR.
140 \$ ( dimag( a( i, j ) ).LT.-rmax ) .OR.
141 \$ ( dimag( a( i, j ) ).GT.rmax ) ) THEN
142 info = 1
143 GO TO 30
144 END IF
145 sa( i, j ) = cmplx( a( i, j ) )
146 10 CONTINUE
147 20 CONTINUE
148 info = 0
149 30 CONTINUE
150 RETURN
151*
152* End of ZLAG2C
153*
154 END
subroutine zlag2c(m, n, a, lda, sa, ldsa, info)
ZLAG2C converts a complex double precision matrix to a complex single precision matrix.
Definition zlag2c.f:107