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
|
/* dlasdt.f -- translated by f2c (version 20061008).
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
*/
#include "f2c.h"
#include "blaswrap.h"
/* Subroutine */ int dlasdt_(integer *n, integer *lvl, integer *nd, integer *
inode, integer *ndiml, integer *ndimr, integer *msub)
{
/* System generated locals */
integer i__1, i__2;
/* Builtin functions */
double log(doublereal);
/* Local variables */
integer i__, il, ir, maxn;
doublereal temp;
integer nlvl, llst, ncrnt;
/* -- LAPACK auxiliary routine (version 3.2) -- */
/* Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
/* November 2006 */
/* .. Scalar Arguments .. */
/* .. */
/* .. Array Arguments .. */
/* .. */
/* Purpose */
/* ======= */
/* DLASDT creates a tree of subproblems for bidiagonal divide and */
/* conquer. */
/* Arguments */
/* ========= */
/* N (input) INTEGER */
/* On entry, the number of diagonal elements of the */
/* bidiagonal matrix. */
/* LVL (output) INTEGER */
/* On exit, the number of levels on the computation tree. */
/* ND (output) INTEGER */
/* On exit, the number of nodes on the tree. */
/* INODE (output) INTEGER array, dimension ( N ) */
/* On exit, centers of subproblems. */
/* NDIML (output) INTEGER array, dimension ( N ) */
/* On exit, row dimensions of left children. */
/* NDIMR (output) INTEGER array, dimension ( N ) */
/* On exit, row dimensions of right children. */
/* MSUB (input) INTEGER. */
/* On entry, the maximum row dimension each subproblem at the */
/* bottom of the tree can be of. */
/* Further Details */
/* =============== */
/* Based on contributions by */
/* Ming Gu and Huan Ren, Computer Science Division, University of */
/* California at Berkeley, USA */
/* ===================================================================== */
/* .. Parameters .. */
/* .. */
/* .. Local Scalars .. */
/* .. */
/* .. Intrinsic Functions .. */
/* .. */
/* .. Executable Statements .. */
/* Find the number of levels on the tree. */
/* Parameter adjustments */
--ndimr;
--ndiml;
--inode;
/* Function Body */
maxn = max(1,*n);
temp = log((doublereal) maxn / (doublereal) (*msub + 1)) / log(2.);
*lvl = (integer) temp + 1;
i__ = *n / 2;
inode[1] = i__ + 1;
ndiml[1] = i__;
ndimr[1] = *n - i__ - 1;
il = 0;
ir = 1;
llst = 1;
i__1 = *lvl - 1;
for (nlvl = 1; nlvl <= i__1; ++nlvl) {
/* Constructing the tree at (NLVL+1)-st level. The number of */
/* nodes created on this level is LLST * 2. */
i__2 = llst - 1;
for (i__ = 0; i__ <= i__2; ++i__) {
il += 2;
ir += 2;
ncrnt = llst + i__;
ndiml[il] = ndiml[ncrnt] / 2;
ndimr[il] = ndiml[ncrnt] - ndiml[il] - 1;
inode[il] = inode[ncrnt] - ndimr[il] - 1;
ndiml[ir] = ndimr[ncrnt] / 2;
ndimr[ir] = ndimr[ncrnt] - ndiml[ir] - 1;
inode[ir] = inode[ncrnt] + ndiml[ir] + 1;
/* L10: */
}
llst <<= 1;
/* L20: */
}
*nd = (llst << 1) - 1;
return 0;
/* End of DLASDT */
} /* dlasdt_ */
|
