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
|
/* eispack/balbak.f -- translated by f2c (version 20050501).
You must link the resulting object file with libf2c:
on Microsoft Windows system, link with libf2c.lib;
on Linux or Unix systems, link with .../path/to/libf2c.a -lm
or, if you install libf2c.a in a standard place, with -lf2c -lm
-- in that order, at the end of the command line, as in
cc *.o -lf2c -lm
Source for libf2c is in /netlib/f2c/libf2c.zip, e.g.,
http://www.netlib.org/f2c/libf2c.zip
*/
#ifdef __cplusplus
extern "C" {
#endif
#include "v3p_netlib.h"
/*< subroutine balbak(nm,n,low,igh,scale,m,z) >*/
/* Subroutine */ int balbak_(integer *nm, integer *n, integer *low, integer *
igh, doublereal *scale, integer *m, doublereal *z__)
{
/* System generated locals */
integer z_dim1, z_offset, i__1, i__2;
/* Local variables */
integer i__, j, k;
doublereal s;
integer ii;
/*< integer i,j,k,m,n,ii,nm,igh,low >*/
/*< double precision scale(n),z(nm,m) >*/
/*< double precision s >*/
/* this subroutine is a translation of the algol procedure balbak, */
/* num. math. 13, 293-304(1969) by parlett and reinsch. */
/* handbook for auto. comp., vol.ii-linear algebra, 315-326(1971). */
/* this subroutine forms the eigenvectors of a real general */
/* matrix by back transforming those of the corresponding */
/* balanced matrix determined by balanc. */
/* on input */
/* nm must be set to the row dimension of two-dimensional */
/* array parameters as declared in the calling program */
/* dimension statement. */
/* n is the order of the matrix. */
/* low and igh are integers determined by balanc. */
/* scale contains information determining the permutations */
/* and scaling factors used by balanc. */
/* m is the number of columns of z to be back transformed. */
/* z contains the real and imaginary parts of the eigen- */
/* vectors to be back transformed in its first m columns. */
/* on output */
/* z contains the real and imaginary parts of the */
/* transformed eigenvectors in its first m columns. */
/* questions and comments should be directed to burton s. garbow, */
/* mathematics and computer science div, argonne national laboratory */
/* this version dated august 1983. */
/* ------------------------------------------------------------------ */
/*< if (m .eq. 0) go to 200 >*/
/* Parameter adjustments */
--scale;
z_dim1 = *nm;
z_offset = 1 + z_dim1;
z__ -= z_offset;
/* Function Body */
if (*m == 0) {
goto L200;
}
/*< if (igh .eq. low) go to 120 >*/
if (*igh == *low) {
goto L120;
}
/*< do 110 i = low, igh >*/
i__1 = *igh;
for (i__ = *low; i__ <= i__1; ++i__) {
/*< s = scale(i) >*/
s = scale[i__];
/* .......... left hand eigenvectors are back transformed */
/* if the foregoing statement is replaced by */
/* s=1.0d0/scale(i). .......... */
/*< do 100 j = 1, m >*/
i__2 = *m;
for (j = 1; j <= i__2; ++j) {
/*< 100 z(i,j) = z(i,j) * s >*/
/* L100: */
z__[i__ + j * z_dim1] *= s;
}
/*< 110 continue >*/
/* L110: */
}
/* ......... for i=low-1 step -1 until 1, */
/* igh+1 step 1 until n do -- .......... */
/*< 120 do 140 ii = 1, n >*/
L120:
i__1 = *n;
for (ii = 1; ii <= i__1; ++ii) {
/*< i = ii >*/
i__ = ii;
/*< if (i .ge. low .and. i .le. igh) go to 140 >*/
if (i__ >= *low && i__ <= *igh) {
goto L140;
}
/*< if (i .lt. low) i = low - ii >*/
if (i__ < *low) {
i__ = *low - ii;
}
/*< k = scale(i) >*/
k = (integer) scale[i__];
/*< if (k .eq. i) go to 140 >*/
if (k == i__) {
goto L140;
}
/*< do 130 j = 1, m >*/
i__2 = *m;
for (j = 1; j <= i__2; ++j) {
/*< s = z(i,j) >*/
s = z__[i__ + j * z_dim1];
/*< z(i,j) = z(k,j) >*/
z__[i__ + j * z_dim1] = z__[k + j * z_dim1];
/*< z(k,j) = s >*/
z__[k + j * z_dim1] = s;
/*< 130 continue >*/
/* L130: */
}
/*< 140 continue >*/
L140:
;
}
/*< 200 return >*/
L200:
return 0;
/*< end >*/
} /* balbak_ */
#ifdef __cplusplus
}
#endif
|
