GRASS GIS 7 Programmer's Manual  7.5.svn(2018)-r72636
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n_les.c
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1 
2 /*****************************************************************************
3 *
4 * MODULE: Grass PDE Numerical Library
5 * AUTHOR(S): Soeren Gebbert, Berlin (GER) Dec 2006
6 * soerengebbert <at> gmx <dot> de
7 *
8 * PURPOSE: functions to manage linear equation systems
9 * part of the gpde library
10 *
11 * COPYRIGHT: (C) 2000 by the GRASS Development Team
12 *
13 * This program is free software under the GNU General Public
14 * License (>=v2). Read the file COPYING that comes with GRASS
15 * for details.
16 *
17 *****************************************************************************/
18 
19 #include <stdlib.h>
20 #include <grass/N_pde.h>
21 #include <grass/gmath.h>
22 
23 
24 /*!
25  * \brief Allocate memory for a (not) quadratic linear equation system which includes the Matrix A, vector x and vector b
26  *
27  * This function calls #N_alloc_les_param
28  *
29  * \param cols int
30  * \param rows int
31  * \param type int
32  * \return N_les *
33  *
34  * */
35 N_les *N_alloc_nquad_les(int cols, int rows, int type)
36 {
37  return N_alloc_les_param(cols, rows, type, 2);
38 }
39 
40 /*!
41  * \brief Allocate memory for a (not) quadratic linear equation system which includes the Matrix A and vector x
42  *
43  * This function calls #N_alloc_les_param
44  *
45  * \param cols int
46  * \param rows int
47  * \param type int
48  * \return N_les *
49  *
50  * */
51 N_les *N_alloc_nquad_les_Ax(int cols, int rows, int type)
52 {
53  return N_alloc_les_param(cols, rows, type, 1);
54 }
55 
56 /*!
57  * \brief Allocate memory for a (not) quadratic linear equation system which includes the Matrix A
58  *
59  * This function calls #N_alloc_les_param
60  *
61  * \param cols int
62  * \param rows int
63  * \param type int
64  * \return N_les *
65  *
66  * */
67 N_les *N_alloc_nquad_les_A(int cols, int rows, int type)
68 {
69  return N_alloc_les_param(cols, rows, type, 0);
70 }
71 
72 /*!
73  * \brief Allocate memory for a (not) quadratic linear equation system which includes the Matrix A, vector x and vector b
74  *
75  * This function calls #N_alloc_les_param
76  *
77  * \param cols int
78  * \param rows int
79  * \param type int
80  * \return N_les *
81  *
82  * */
83 N_les *N_alloc_nquad_les_Ax_b(int cols, int rows, int type)
84 {
85  return N_alloc_les_param(cols, rows, type, 2);
86 }
87 
88 
89 
90 /*!
91  * \brief Allocate memory for a quadratic linear equation system which includes the Matrix A, vector x and vector b
92  *
93  * This function calls #N_alloc_les_param
94  *
95  * \param rows int
96  * \param type int
97  * \return N_les *
98  *
99  * */
100 N_les *N_alloc_les(int rows, int type)
101 {
102  return N_alloc_les_param(rows, rows, type, 2);
103 }
104 
105 /*!
106  * \brief Allocate memory for a quadratic linear equation system which includes the Matrix A and vector x
107  *
108  * This function calls #N_alloc_les_param
109  *
110  * \param rows int
111  * \param type int
112  * \return N_les *
113  *
114  * */
115 N_les *N_alloc_les_Ax(int rows, int type)
116 {
117  return N_alloc_les_param(rows, rows, type, 1);
118 }
119 
120 /*!
121  * \brief Allocate memory for a quadratic linear equation system which includes the Matrix A
122  *
123  * This function calls #N_alloc_les_param
124  *
125  * \param rows int
126  * \param type int
127  * \return N_les *
128  *
129  * */
130 N_les *N_alloc_les_A(int rows, int type)
131 {
132  return N_alloc_les_param(rows, rows, type, 0);
133 }
134 
135 /*!
136  * \brief Allocate memory for a quadratic linear equation system which includes the Matrix A, vector x and vector b
137  *
138  * This function calls #N_alloc_les_param
139  *
140  * \param rows int
141  * \param type int
142  * \return N_les *
143  *
144  * */
145 N_les *N_alloc_les_Ax_b(int rows, int type)
146 {
147  return N_alloc_les_param(rows, rows, type, 2);
148 }
149 
150 
151 /*!
152  * \brief Allocate memory for a quadratic or not quadratic linear equation system
153  *
154  * The type of the linear equation system must be N_NORMAL_LES for
155  * a regular quadratic matrix or N_SPARSE_LES for a sparse matrix
156  *
157  * <p>
158  * In case of N_NORMAL_LES
159  *
160  * A quadratic matrix of size rows*rows*sizeof(double) will allocated
161  *
162  * <p>
163  * In case of N_SPARSE_LES
164  *
165  * a vector of size row will be allocated, ready to hold additional allocated sparse vectors.
166  * each sparse vector may have a different size.
167  *
168  * Parameter parts defines which parts of the les should be allocated.
169  * The number of columns and rows defines if the matrix is quadratic.
170  *
171  * \param cols int
172  * \param rows int
173  * \param type int
174  * \param parts int -- 2 = A, x and b; 1 = A and x; 0 = A allocated
175  * \return N_les *
176  *
177  * */
178 N_les *N_alloc_les_param(int cols, int rows, int type, int parts)
179 {
180  N_les *les;
181 
182  int i;
183 
184  if (type == N_SPARSE_LES)
185  G_debug(2,
186  "Allocate memory for a sparse linear equation system with %i rows\n",
187  rows);
188  else
189  G_debug(2,
190  "Allocate memory for a regular linear equation system with %i rows\n",
191  rows);
192 
193  les = (N_les *) G_calloc(1, sizeof(N_les));
194 
195  if (parts > 0) {
196  les->x = (double *)G_calloc(cols, sizeof(double));
197  for (i = 0; i < cols; i++)
198  les->x[i] = 0.0;
199  }
200 
201 
202  if (parts > 1) {
203  les->b = (double *)G_calloc(cols, sizeof(double));
204  for (i = 0; i < cols; i++)
205  les->b[i] = 0.0;
206  }
207 
208  les->A = NULL;
209  les->Asp = NULL;
210  les->rows = rows;
211  les->cols = cols;
212  if (rows == cols)
213  les->quad = 1;
214  else
215  les->quad = 0;
216 
217  if (type == N_SPARSE_LES) {
218  les->Asp = G_math_alloc_spmatrix(rows);
219  les->type = N_SPARSE_LES;
220  }
221  else {
222  les->A = G_alloc_matrix(rows, cols);
223  les->type = N_NORMAL_LES;
224  }
225 
226  return les;
227 }
228 
229 /*!
230  *
231  * \brief prints the linear equation system to stdout
232  *
233  * <p>
234  * Format:
235  * A*x = b
236  *
237  * <p>
238  * Example
239  \verbatim
240 
241  2 1 1 1 * 2 = 0.1
242  1 2 0 0 * 3 = 0.2
243  1 0 2 0 * 3 = 0.2
244  1 0 0 2 * 2 = 0.1
245 
246  \endverbatim
247  *
248  * \param les N_les *
249  * \return void
250  *
251  * */
252 void N_print_les(N_les * les)
253 {
254  int i, j, k, out;
255 
256 
257  if (les->type == N_SPARSE_LES) {
258  for (i = 0; i < les->rows; i++) {
259  for (j = 0; j < les->cols; j++) {
260  out = 0;
261  for (k = 0; k < les->Asp[i]->cols; k++) {
262  if (les->Asp[i]->index[k] == j) {
263  fprintf(stdout, "%4.5f ", les->Asp[i]->values[k]);
264  out = 1;
265  }
266  }
267  if (!out)
268  fprintf(stdout, "%4.5f ", 0.0);
269  }
270  if (les->x)
271  fprintf(stdout, " * %4.5f", les->x[i]);
272  if (les->b)
273  fprintf(stdout, " = %4.5f ", les->b[i]);
274 
275  fprintf(stdout, "\n");
276  }
277  }
278  else {
279 
280  for (i = 0; i < les->rows; i++) {
281  for (j = 0; j < les->cols; j++) {
282  fprintf(stdout, "%4.5f ", les->A[i][j]);
283  }
284  if (les->x)
285  fprintf(stdout, " * %4.5f", les->x[i]);
286  if (les->b)
287  fprintf(stdout, " = %4.5f ", les->b[i]);
288 
289  fprintf(stdout, "\n");
290  }
291 
292  }
293  return;
294 }
295 
296 /*!
297  * \brief Release the memory of the linear equation system
298  *
299  * \param les N_les *
300  * \return void
301  *
302  * */
303 
304 void N_free_les(N_les * les)
305 {
306  if (les->type == N_SPARSE_LES)
307  G_debug(2, "Releasing memory of a sparse linear equation system\n");
308  else
309  G_debug(2, "Releasing memory of a regular linear equation system\n");
310 
311  if (les) {
312 
313  if (les->x)
314  G_free(les->x);
315  if (les->b)
316  G_free(les->b);
317 
318  if (les->type == N_SPARSE_LES) {
319 
320  if (les->Asp) {
321  G_math_free_spmatrix(les->Asp, les->rows);
322  }
323  }
324  else {
325 
326  if (les->A) {
327  G_free_matrix(les->A);
328  }
329  }
330 
331  free(les);
332  }
333 
334  return;
335 }
void G_free(void *buf)
Free allocated memory.
Definition: gis/alloc.c:149
N_les * N_alloc_nquad_les_Ax_b(int cols, int rows, int type)
Allocate memory for a (not) quadratic linear equation system which includes the Matrix A...
Definition: n_les.c:83
N_les * N_alloc_les_Ax_b(int rows, int type)
Allocate memory for a quadratic linear equation system which includes the Matrix A, vector x and vector b.
Definition: n_les.c:145
int quad
Definition: N_pde.h:80
double ** G_alloc_matrix(int rows, int cols)
Matrix memory allocation.
Definition: dalloc.c:60
#define N_SPARSE_LES
Definition: N_pde.h:27
N_les * N_alloc_les(int rows, int type)
Allocate memory for a quadratic linear equation system which includes the Matrix A, vector x and vector b.
Definition: n_les.c:100
void free(void *)
#define NULL
Definition: ccmath.h:32
double * x
Definition: N_pde.h:74
unsigned int * index
Definition: gmath.h:58
void N_free_les(N_les *les)
Release the memory of the linear equation system.
Definition: n_les.c:304
N_les * N_alloc_les_Ax(int rows, int type)
Allocate memory for a quadratic linear equation system which includes the Matrix A and vector x...
Definition: n_les.c:115
double ** A
Definition: N_pde.h:76
G_math_spvector ** G_math_alloc_spmatrix(int rows)
Allocate memory for a sparse matrix.
Definition: sparse_matrix.c:58
void N_print_les(N_les *les)
prints the linear equation system to stdout
Definition: n_les.c:252
N_les * N_alloc_nquad_les_Ax(int cols, int rows, int type)
Allocate memory for a (not) quadratic linear equation system which includes the Matrix A and vector x...
Definition: n_les.c:51
N_les * N_alloc_nquad_les_A(int cols, int rows, int type)
Allocate memory for a (not) quadratic linear equation system which includes the Matrix A...
Definition: n_les.c:67
int G_debug(int level, const char *msg,...)
Print debugging message.
Definition: debug.c:65
double * values
Definition: gmath.h:56
G_math_spvector ** Asp
Definition: N_pde.h:77
void G_free_matrix(double **m)
Matrix memory deallocation.
Definition: dalloc.c:169
unsigned int cols
Definition: gmath.h:57
N_les * N_alloc_les_param(int cols, int rows, int type, int parts)
Allocate memory for a quadratic or not quadratic linear equation system.
Definition: n_les.c:178
N_les * N_alloc_nquad_les(int cols, int rows, int type)
Allocate memory for a (not) quadratic linear equation system which includes the Matrix A...
Definition: n_les.c:35
N_les * N_alloc_les_A(int rows, int type)
Allocate memory for a quadratic linear equation system which includes the Matrix A.
Definition: n_les.c:130
int cols
Number of columns for 2D data.
Definition: gis.h:409
int cols
Definition: N_pde.h:79
double * b
Definition: N_pde.h:75
#define N_NORMAL_LES
Definition: N_pde.h:26
int rows
Definition: N_pde.h:78
void G_math_free_spmatrix(G_math_spvector **Asp, int rows)
Release the memory of the sparse matrix.
int rows
Number of rows for 2D data.
Definition: gis.h:405
The linear equation system (les) structure.
Definition: N_pde.h:72
int type
Definition: N_pde.h:81