|
2928
|
1 /* |
|
|
2 |
|
|
3 Copyright (C) 1996, 1997 John W. Eaton |
|
|
4 |
|
|
5 This file is part of Octave. |
|
|
6 |
|
|
7 Octave is free software; you can redistribute it and/or modify it |
|
|
8 under the terms of the GNU General Public License as published by the |
|
|
9 Free Software Foundation; either version 2, or (at your option) any |
|
|
10 later version. |
|
|
11 |
|
|
12 Octave is distributed in the hope that it will be useful, but WITHOUT |
|
|
13 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
|
|
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
|
|
15 for more details. |
|
|
16 |
|
|
17 You should have received a copy of the GNU General Public License |
|
|
18 along with Octave; see the file COPYING. If not, write to the Free |
|
|
19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
|
|
20 |
|
|
21 */ |
|
|
22 |
|
|
23 #ifdef HAVE_CONFIG_H |
|
|
24 #include <config.h> |
|
|
25 #endif |
|
|
26 |
|
4153
|
27 #include "quit.h" |
|
|
28 |
|
2928
|
29 #include "defun-dld.h" |
|
|
30 #include "error.h" |
|
|
31 #include "gripes.h" |
|
|
32 #include "oct-obj.h" |
|
|
33 |
|
3418
|
34 #define DO_FIND_OP(T) \ |
|
|
35 do \ |
|
|
36 { \ |
|
|
37 T tmp (count); \ |
|
|
38 \ |
|
|
39 for (int i = 0; i < count; i++) \ |
|
4628
|
40 tmp (i) = nr * (j_idx(i) - 1.0) + i_idx(i); \ |
|
3418
|
41 \ |
|
|
42 retval(0) = tmp; \ |
|
|
43 } \ |
|
|
44 while (0) |
|
|
45 |
|
|
46 |
|
2928
|
47 static octave_value_list |
|
|
48 find_to_fortran_idx (const ColumnVector i_idx, const ColumnVector j_idx, |
|
|
49 const octave_value& val, int nr, int nargout) |
|
|
50 { |
|
|
51 octave_value_list retval; |
|
|
52 |
|
|
53 switch (nargout) |
|
|
54 { |
|
|
55 case 0: |
|
|
56 case 1: |
|
|
57 { |
|
|
58 // If the original argument was a row vector, force a row |
|
|
59 // vector of indices to be returned. |
|
|
60 |
|
3418
|
61 int count = i_idx.length (); |
|
|
62 |
|
|
63 if (nr == 1) |
|
4628
|
64 DO_FIND_OP (RowVector); |
|
3418
|
65 else |
|
4628
|
66 DO_FIND_OP (ColumnVector); |
|
2928
|
67 } |
|
|
68 break; |
|
|
69 |
|
|
70 case 3: |
|
|
71 retval(2) = val; |
|
|
72 // Fall through! |
|
|
73 |
|
|
74 case 2: |
|
3418
|
75 retval(1) = j_idx; |
|
|
76 retval(0) = i_idx; |
|
2928
|
77 break; |
|
|
78 |
|
|
79 default: |
|
|
80 panic_impossible (); |
|
|
81 break; |
|
|
82 } |
|
|
83 |
|
|
84 return retval; |
|
|
85 } |
|
|
86 |
|
|
87 static octave_value_list |
|
|
88 find_nonzero_elem_idx (const Matrix& m, int nargout) |
|
|
89 { |
|
|
90 int count = 0; |
|
|
91 int m_nr = m.rows (); |
|
|
92 int m_nc = m.columns (); |
|
|
93 |
|
|
94 int i, j; |
|
|
95 for (j = 0; j < m_nc; j++) |
|
|
96 for (i = 0; i < m_nr; i++) |
|
4153
|
97 { |
|
|
98 OCTAVE_QUIT; |
|
|
99 |
|
|
100 if (m (i, j) != 0.0) |
|
|
101 count++; |
|
|
102 } |
|
2928
|
103 |
|
|
104 octave_value_list retval (((nargout == 0) ? 1 : nargout), Matrix ()); |
|
|
105 |
|
|
106 if (count == 0) |
|
|
107 return retval; |
|
|
108 |
|
|
109 ColumnVector i_idx (count); |
|
|
110 ColumnVector j_idx (count); |
|
|
111 ColumnVector v (count); |
|
|
112 |
|
|
113 count = 0; |
|
|
114 for (j = 0; j < m_nc; j++) |
|
|
115 for (i = 0; i < m_nr; i++) |
|
|
116 { |
|
4153
|
117 OCTAVE_QUIT; |
|
|
118 |
|
2928
|
119 double d = m (i, j); |
|
|
120 if (d != 0.0) |
|
|
121 { |
|
|
122 i_idx (count) = i + 1; |
|
|
123 j_idx (count) = j + 1; |
|
|
124 v (count) = d; |
|
|
125 count++; |
|
|
126 } |
|
|
127 } |
|
|
128 |
|
3418
|
129 return find_to_fortran_idx (i_idx, j_idx, octave_value (v), m_nr, nargout); |
|
2928
|
130 } |
|
|
131 |
|
|
132 static octave_value_list |
|
|
133 find_nonzero_elem_idx (const ComplexMatrix& m, int nargout) |
|
|
134 { |
|
|
135 int count = 0; |
|
|
136 int m_nr = m.rows (); |
|
|
137 int m_nc = m.columns (); |
|
|
138 |
|
|
139 int i, j; |
|
|
140 for (j = 0; j < m_nc; j++) |
|
|
141 for (i = 0; i < m_nr; i++) |
|
4153
|
142 { |
|
|
143 OCTAVE_QUIT; |
|
|
144 |
|
|
145 if (m (i, j) != 0.0) |
|
|
146 count++; |
|
|
147 } |
|
2928
|
148 |
|
|
149 octave_value_list retval (((nargout == 0) ? 1 : nargout), Matrix ()); |
|
|
150 |
|
|
151 if (count == 0) |
|
|
152 return retval; |
|
|
153 |
|
|
154 ColumnVector i_idx (count); |
|
|
155 ColumnVector j_idx (count); |
|
|
156 ComplexColumnVector v (count); |
|
|
157 |
|
|
158 count = 0; |
|
|
159 for (j = 0; j < m_nc; j++) |
|
|
160 for (i = 0; i < m_nr; i++) |
|
|
161 { |
|
4153
|
162 OCTAVE_QUIT; |
|
|
163 |
|
2928
|
164 Complex c = m (i, j); |
|
|
165 if (c != 0.0) |
|
|
166 { |
|
|
167 i_idx (count) = i + 1; |
|
|
168 j_idx (count) = j + 1; |
|
|
169 v (count) = c; |
|
|
170 count++; |
|
|
171 } |
|
|
172 } |
|
|
173 |
|
3418
|
174 return find_to_fortran_idx (i_idx, j_idx, octave_value (v), m_nr, nargout); |
|
2928
|
175 } |
|
|
176 |
|
|
177 DEFUN_DLD (find, args, nargout, |
|
3369
|
178 "-*- texinfo -*-\n\ |
|
|
179 @deftypefn {Loadable Function} {} find (@var{x})\n\ |
|
|
180 Return a vector of indices of nonzero elements of a matrix. To obtain a\n\ |
|
|
181 single index for each matrix element, Octave pretends that the columns\n\ |
|
|
182 of a matrix form one long vector (like Fortran arrays are stored). For\n\ |
|
|
183 example,\n\ |
|
|
184 \n\ |
|
|
185 @example\n\ |
|
|
186 @group\n\ |
|
|
187 find (eye (2))\n\ |
|
|
188 @result{} [ 1; 4 ]\n\ |
|
|
189 @end group\n\ |
|
|
190 @end example\n\ |
|
|
191 \n\ |
|
|
192 If two outputs are requested, @code{find} returns the row and column\n\ |
|
|
193 indices of nonzero elements of a matrix. For example,\n\ |
|
|
194 \n\ |
|
|
195 @example\n\ |
|
|
196 @group\n\ |
|
|
197 [i, j] = find (2 * eye (2))\n\ |
|
|
198 @result{} i = [ 1; 2 ]\n\ |
|
|
199 @result{} j = [ 1; 2 ]\n\ |
|
|
200 @end group\n\ |
|
|
201 @end example\n\ |
|
|
202 \n\ |
|
|
203 If three outputs are requested, @code{find} also returns a vector\n\ |
|
|
204 containing the nonzero values. For example,\n\ |
|
|
205 \n\ |
|
|
206 @example\n\ |
|
|
207 @group\n\ |
|
|
208 [i, j, v] = find (3 * eye (2))\n\ |
|
|
209 @result{} i = [ 1; 2 ]\n\ |
|
|
210 @result{} j = [ 1; 2 ]\n\ |
|
|
211 @result{} v = [ 3; 3 ]\n\ |
|
|
212 @end group\n\ |
|
|
213 @end example\n\ |
|
|
214 @end deftypefn") |
|
2928
|
215 { |
|
|
216 octave_value_list retval; |
|
|
217 |
|
|
218 int nargin = args.length (); |
|
|
219 |
|
|
220 if (nargin != 1 || nargout > 3) |
|
|
221 { |
|
|
222 print_usage ("find"); |
|
|
223 return retval; |
|
|
224 } |
|
|
225 |
|
|
226 octave_value arg = args(0); |
|
|
227 |
|
|
228 if (arg.is_real_type ()) |
|
|
229 { |
|
|
230 Matrix m = arg.matrix_value (); |
|
|
231 |
|
|
232 if (! error_state) |
|
|
233 retval = find_nonzero_elem_idx (m, nargout); |
|
|
234 } |
|
|
235 else if (arg.is_complex_type ()) |
|
|
236 { |
|
|
237 ComplexMatrix m = arg.complex_matrix_value (); |
|
|
238 |
|
|
239 if (! error_state) |
|
|
240 retval = find_nonzero_elem_idx (m, nargout); |
|
|
241 } |
|
|
242 else |
|
|
243 { |
|
|
244 gripe_wrong_type_arg ("find", arg); |
|
|
245 } |
|
|
246 |
|
|
247 return retval; |
|
|
248 } |
|
|
249 |
|
|
250 /* |
|
|
251 ;;; Local Variables: *** |
|
|
252 ;;; mode: C++ *** |
|
|
253 ;;; End: *** |
|
|
254 */ |
