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
|
/* linpack/dposl.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"
/* Table of constant values */
static integer c__1 = 1;
/*< subroutine dposl(a,lda,n,b) >*/
/* Subroutine */ int dposl_(doublereal *a, integer *lda, integer *n,
doublereal *b)
{
/* System generated locals */
integer a_dim1, a_offset, i__1, i__2;
/* Local variables */
integer k;
doublereal t;
integer kb;
extern doublereal ddot_(integer *, doublereal *, integer *, doublereal *,
integer *);
extern /* Subroutine */ int daxpy_(integer *, doublereal *, doublereal *,
integer *, doublereal *, integer *);
/*< integer lda,n >*/
/*< double precision a(lda,1),b(1) >*/
/* dposl solves the double precision symmetric positive definite */
/* system a * x = b */
/* using the factors computed by dpoco or dpofa. */
/* on entry */
/* a double precision(lda, n) */
/* the output from dpoco or dpofa. */
/* lda integer */
/* the leading dimension of the array a . */
/* n integer */
/* the order of the matrix a . */
/* b double precision(n) */
/* the right hand side vector. */
/* on return */
/* b the solution vector x . */
/* error condition */
/* a division by zero will occur if the input factor contains */
/* a zero on the diagonal. technically this indicates */
/* singularity but it is usually caused by improper subroutine */
/* arguments. it will not occur if the subroutines are called */
/* correctly and info .eq. 0 . */
/* to compute inverse(a) * c where c is a matrix */
/* with p columns */
/* call dpoco(a,lda,n,rcond,z,info) */
/* if (rcond is too small .or. info .ne. 0) go to ... */
/* do 10 j = 1, p */
/* call dposl(a,lda,n,c(1,j)) */
/* 10 continue */
/* linpack. this version dated 08/14/78 . */
/* cleve moler, university of new mexico, argonne national lab. */
/* subroutines and functions */
/* blas daxpy,ddot */
/* internal variables */
/*< double precision ddot,t >*/
/*< integer k,kb >*/
/* solve trans(r)*y = b */
/*< do 10 k = 1, n >*/
/* Parameter adjustments */
a_dim1 = *lda;
a_offset = 1 + a_dim1;
a -= a_offset;
--b;
/* Function Body */
i__1 = *n;
for (k = 1; k <= i__1; ++k) {
/*< t = ddot(k-1,a(1,k),1,b(1),1) >*/
i__2 = k - 1;
t = ddot_(&i__2, &a[k * a_dim1 + 1], &c__1, &b[1], &c__1);
/*< b(k) = (b(k) - t)/a(k,k) >*/
b[k] = (b[k] - t) / a[k + k * a_dim1];
/*< 10 continue >*/
/* L10: */
}
/* solve r*x = y */
/*< do 20 kb = 1, n >*/
i__1 = *n;
for (kb = 1; kb <= i__1; ++kb) {
/*< k = n + 1 - kb >*/
k = *n + 1 - kb;
/*< b(k) = b(k)/a(k,k) >*/
b[k] /= a[k + k * a_dim1];
/*< t = -b(k) >*/
t = -b[k];
/*< call daxpy(k-1,t,a(1,k),1,b(1),1) >*/
i__2 = k - 1;
daxpy_(&i__2, &t, &a[k * a_dim1 + 1], &c__1, &b[1], &c__1);
/*< 20 continue >*/
/* L20: */
}
/*< return >*/
return 0;
/*< end >*/
} /* dposl_ */
#ifdef __cplusplus
}
#endif
|
