File: zqrt13.f

package info (click to toggle)
lapack 3.12.1-4
  • links: PTS, VCS
  • area: main
  • in suites: sid, trixie
  • size: 78,908 kB
  • sloc: fortran: 622,840; ansic: 217,704; f90: 6,041; makefile: 5,100; sh: 326; python: 270; xml: 182
file content (172 lines) | stat: -rw-r--r-- 4,143 bytes parent folder | download
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
*> \brief \b ZQRT13
*
*  =========== DOCUMENTATION ===========
*
* Online html documentation available at
*            http://www.netlib.org/lapack/explore-html/
*
*  Definition:
*  ===========
*
*       SUBROUTINE ZQRT13( SCALE, M, N, A, LDA, NORMA, ISEED )
*
*       .. Scalar Arguments ..
*       INTEGER            LDA, M, N, SCALE
*       DOUBLE PRECISION   NORMA
*       ..
*       .. Array Arguments ..
*       INTEGER            ISEED( 4 )
*       COMPLEX*16         A( LDA, * )
*       ..
*
*
*> \par Purpose:
*  =============
*>
*> \verbatim
*>
*> ZQRT13 generates a full-rank matrix that may be scaled to have large
*> or small norm.
*> \endverbatim
*
*  Arguments:
*  ==========
*
*> \param[in] SCALE
*> \verbatim
*>          SCALE is INTEGER
*>          SCALE = 1: normally scaled matrix
*>          SCALE = 2: matrix scaled up
*>          SCALE = 3: matrix scaled down
*> \endverbatim
*>
*> \param[in] M
*> \verbatim
*>          M is INTEGER
*>          The number of rows of the matrix A.
*> \endverbatim
*>
*> \param[in] N
*> \verbatim
*>          N is INTEGER
*>          The number of columns of A.
*> \endverbatim
*>
*> \param[out] A
*> \verbatim
*>          A is COMPLEX*16 array, dimension (LDA,N)
*>          The M-by-N matrix A.
*> \endverbatim
*>
*> \param[in] LDA
*> \verbatim
*>          LDA is INTEGER
*>          The leading dimension of the array A.
*> \endverbatim
*>
*> \param[out] NORMA
*> \verbatim
*>          NORMA is DOUBLE PRECISION
*>          The one-norm of A.
*> \endverbatim
*>
*> \param[in,out] ISEED
*> \verbatim
*>          ISEED is integer array, dimension (4)
*>          Seed for random number generator
*> \endverbatim
*
*  Authors:
*  ========
*
*> \author Univ. of Tennessee
*> \author Univ. of California Berkeley
*> \author Univ. of Colorado Denver
*> \author NAG Ltd.
*
*> \ingroup complex16_lin
*
*  =====================================================================
      SUBROUTINE ZQRT13( SCALE, M, N, A, LDA, NORMA, ISEED )
*
*  -- LAPACK test routine --
*  -- LAPACK is a software package provided by Univ. of Tennessee,    --
*  -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
*
*     .. Scalar Arguments ..
      INTEGER            LDA, M, N, SCALE
      DOUBLE PRECISION   NORMA
*     ..
*     .. Array Arguments ..
      INTEGER            ISEED( 4 )
      COMPLEX*16         A( LDA, * )
*     ..
*
*  =====================================================================
*
*     .. Parameters ..
      DOUBLE PRECISION   ONE
      PARAMETER          ( ONE = 1.0D0 )
*     ..
*     .. Local Scalars ..
      INTEGER            INFO, J
      DOUBLE PRECISION   BIGNUM, SMLNUM
*     ..
*     .. External Functions ..
      DOUBLE PRECISION   DLAMCH, DZASUM, ZLANGE
      EXTERNAL           DLAMCH, DZASUM, ZLANGE
*     ..
*     .. External Subroutines ..
      EXTERNAL           ZLARNV, ZLASCL
*     ..
*     .. Intrinsic Functions ..
      INTRINSIC          DBLE, DCMPLX, SIGN
*     ..
*     .. Local Arrays ..
      DOUBLE PRECISION   DUMMY( 1 )
*     ..
*     .. Executable Statements ..
*
      IF( M.LE.0 .OR. N.LE.0 )
     $   RETURN
*
*     benign matrix
*
      DO 10 J = 1, N
         CALL ZLARNV( 2, ISEED, M, A( 1, J ) )
         IF( J.LE.M ) THEN
            A( J, J ) = A( J, J ) + DCMPLX( SIGN( DZASUM( M, A( 1, J ),
     $                  1 ), DBLE( A( J, J ) ) ) )
         END IF
   10 CONTINUE
*
*     scaled versions
*
      IF( SCALE.NE.1 ) THEN
         NORMA = ZLANGE( 'Max', M, N, A, LDA, DUMMY )
         SMLNUM = DLAMCH( 'Safe minimum' )
         BIGNUM = ONE / SMLNUM
         SMLNUM = SMLNUM / DLAMCH( 'Epsilon' )
         BIGNUM = ONE / SMLNUM
*
         IF( SCALE.EQ.2 ) THEN
*
*           matrix scaled up
*
            CALL ZLASCL( 'General', 0, 0, NORMA, BIGNUM, M, N, A, LDA,
     $                   INFO )
         ELSE IF( SCALE.EQ.3 ) THEN
*
*           matrix scaled down
*
            CALL ZLASCL( 'General', 0, 0, NORMA, SMLNUM, M, N, A, LDA,
     $                   INFO )
         END IF
      END IF
*
      NORMA = ZLANGE( 'One-norm', M, N, A, LDA, DUMMY )
      RETURN
*
*     End of ZQRT13
*
      END