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[project @ 1993-08-08 01:20:23 by jwe] Initial revision
author jwe
date Sun, 08 Aug 1993 01:21:46 +0000
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children 1a48a1b91489
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2:c0190df9885d 3:9a4c07481e61
1 // FEGrid.cc -*- C++ -*-
2 /*
3
4 Copyright (C) 1992, 1993 John W. Eaton
5
6 This file is part of Octave.
7
8 Octave is free software; you can redistribute it and/or modify it
9 under the terms of the GNU General Public License as published by the
10 Free Software Foundation; either version 2, or (at your option) any
11 later version.
12
13 Octave is distributed in the hope that it will be useful, but WITHOUT
14 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16 for more details.
17
18 You should have received a copy of the GNU General Public License
19 along with Octave; see the file COPYING. If not, write to the Free
20 Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
21
22 */
23
24 #ifdef __GNUG__
25 #pragma implementation
26 #endif
27
28 #include "FEGrid.h"
29
30 // error handling
31
32 void
33 FEGrid::error (const char* msg) const
34 {
35 cerr << "Fatal FEGrid error. " << msg << "\n";
36 exit(1);
37 }
38
39 void
40 FEGrid::nel_error (void) const
41 {
42 error ("number of elements less than 1");
43 }
44
45 // Constructors
46
47 FEGrid::FEGrid (int nel, double width)
48 {
49 if (nel < 1)
50 nel_error ();
51
52 elem.resize (nel+1);
53
54 for (int i = 0; i <= nel; i++)
55 elem.elem (i) = i * width;
56 }
57
58 FEGrid::FEGrid (int nel, double left, double right)
59 {
60 if (nel < 1)
61 nel_error ();
62
63 elem.resize (nel+1);
64
65 double width = (right - left) / (double) nel;
66
67 for (int i = 0; i <= nel; i++)
68 elem.elem (i) = i * width + left;
69
70 check_grid ();
71 }
72
73 int
74 FEGrid::element (double x) const
75 {
76 if (! in_bounds (x))
77 error ("value not within grid boundaries");
78
79 int nel = elem.capacity () - 1;
80 for (int i = 1; i <= nel; i++)
81 {
82 if (x >= elem.elem (i-1) && x <= elem.elem (i))
83 return i;
84 }
85 return -1;
86
87 }
88
89 void
90 FEGrid::check_grid (void) const
91 {
92 int nel = elem.capacity () - 1;
93 if (nel < 1)
94 nel_error ();
95
96 for (int i = 1; i <= nel; i++)
97 {
98 if (elem.elem (i-1) > elem.elem (i))
99 error ("element boundaries not in ascending order");
100
101 if (elem.elem (i-1) == elem.elem (i))
102 error ("zero width element");
103 }
104 }
105
106 ostream&
107 operator << (ostream& s, const FEGrid& g)
108 {
109 s << g.element_boundaries ();
110 return s;
111 }
112
113 /*
114 ;;; Local Variables: ***
115 ;;; mode: C++ ***
116 ;;; page-delimiter: "^/\\*" ***
117 ;;; End: ***
118 */