GRASS GIS 7 Programmer's Manual  7.9.dev(2021)-e5379bbd7
point2d.c
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1 /*!
2  * \file point2d.c
3  *
4  * \author
5  * Lubos Mitas (original program and various modifications)
6  *
7  * \author
8  * H. Mitasova,
9  * I. Kosinovsky,
10  * D. Gerdes,
11  * D. McCauley
12  * (GRASS4.1 version of the program and GRASS4.2 modifications)
13  *
14  * \author modified by McCauley in August 1995
15  * \author modified by Mitasova in August 1995, Nov. 1996
16  *
18  * (C) 1993-2006 by Helena Mitasova and the GRASS Development Team
19  *
21  * This program is free software under the
22  * GNU General Public License (>=v2).
23  * Read the file COPYING that comes with GRASS for details.
24  */
25
26
27 #include <stdio.h>
28 #include <math.h>
29 #include <unistd.h>
30 #include <grass/gis.h>
31 #include <grass/vector.h>
32 #include <grass/dbmi.h>
33
34 #define POINT2D_C
35 #include <grass/interpf.h>
36
37 /* needed for AIX */
38 #ifdef hz
39 #undef hz
40 #endif
41
42 /*!
43  * Checks if interpolating function interp() evaluates correct z-values at
44  * given points. If smoothing is used calculate the maximum error caused
45  * by smoothing.
46  *
47  * *ertot* is a RMS deviation of the interpolated surface.
48  *
49  * \todo
50  * Alternative description:
51  * ...calculate the maximum and RMS deviation caused by smoothing.
52  */
54  struct quaddata *data, /*!< current region */
55  double *b, /*!< solution of linear equations */
56  double *ertot, /*!< total error */
57  double zmin, /*!< min z-value */
58  double dnorm,
59  struct triple skip_point
60  )
61 {
62  int n_points = data->n_points; /* number of points */
63  struct triple *points = data->points; /* points for interpolation */
64  double east = data->xmax;
65  double west = data->x_orig;
66  double north = data->ymax;
67  double south = data->y_orig;
68  double rfsta2, errmax, h, xx, yy, r2, hz, zz, err, xmm, ymm, r;
69  double skip_err;
70  int n1, mm, m, cat;
71  double fstar2;
72  int inside;
73
74  /* Site *site; */
75  char buf[1024];
76
77
78  /* if ((site = G_site_new_struct (-1, 2, 0, 1)) == NULL)
79  G_fatal_error ("Memory error for site struct"); */
80
81  fstar2 = params->fi * params->fi / 4.;
82  errmax = .0;
83  n1 = n_points + 1;
84  for (mm = 1; mm <= n_points; mm++) {
85  h = b[0];
86  for (m = 1; m <= n_points; m++) {
87  xx = points[mm - 1].x - points[m - 1].x;
88  yy = points[mm - 1].y - points[m - 1].y;
89  r2 = yy * yy + xx * xx;
90  if (r2 != 0.) {
91  rfsta2 = fstar2 * r2;
92  r = r2;
93  h = h + b[m] * params->interp(r, params->fi);
94  }
95  }
96  /* modified by helena january 1997 - normalization of z was
97  removed from segm2d.c and interp2d.c
98  hz = (h * dnorm) + zmin;
99  zz = (points[mm - 1].z * dnorm) + zmin;
100  */
101  hz = h + zmin;
102  zz = points[mm - 1].z + zmin;
103  err = hz - zz;
104  xmm = points[mm - 1].x * dnorm + params->x_orig + west;
105  ymm = points[mm - 1].y * dnorm + params->y_orig + south;
106  if ((xmm >= west + params->x_orig) && (xmm <= east + params->x_orig)
107  && (ymm >= south + params->y_orig) &&
108  (ymm <= north + params->y_orig))
109  inside = 1;
110  else
111  inside = 0;
112
113  if (params->fddevi != NULL) {
114
115  if (inside) { /* if the point is inside the region */
118
119  Vect_append_point(Pnts, xmm, ymm, zz);
120  cat = count;
121  Vect_cat_set(Cats2, 1, cat);
123
125  sprintf(buf, "insert into %s values ( %d ", ff->table, cat);
126  db_append_string(&sql2, buf);
127
128  sprintf(buf, ", %f", err);
129  db_append_string(&sql2, buf);
130  db_append_string(&sql2, ")");
131  G_debug(3, "IL_check_at_points_2d: %s", db_get_string(&sql2));
132
136  G_fatal_error("Cannot insert new row: %s",
137  db_get_string(&sql2));
138  }
139  count++;
140
141  }
142  }
143  (*ertot) += err * err;
144  }
145
146  /* cv stuff */
147  if (params->cv) {
148  h = b[0];
149  for (m = 1; m <= n_points - 1; m++) {
150  xx = points[m - 1].x - skip_point.x;
151  yy = points[m - 1].y - skip_point.y;
152  r2 = yy * yy + xx * xx;
153  if (r2 != 0.) {
154  rfsta2 = fstar2 * r2;
155  r = r2;
156  h = h + b[m] * params->interp(r, params->fi);
157  }
158  }
159  hz = h + zmin;
160  zz = skip_point.z + zmin;
161  skip_err = hz - zz;
162  xmm = skip_point.x * dnorm + params->x_orig + west;
163  ymm = skip_point.y * dnorm + params->y_orig + south;
164
165  if ((xmm >= west + params->x_orig) && (xmm <= east + params->x_orig)
166  && (ymm >= south + params->y_orig) &&
167  (ymm <= north + params->y_orig))
168  inside = 1;
169  else
170  inside = 0;
171
172  if (inside) { /* if the point is inside the region */
175
176  Vect_append_point(Pnts, xmm, ymm, zz);
177  cat = count;
178  Vect_cat_set(Cats2, 1, cat);
180
182  sprintf(buf, "insert into %s values ( %d ", ff->table, cat);
183  db_append_string(&sql2, buf);
184
185  sprintf(buf, ", %f", skip_err);
186  db_append_string(&sql2, buf);
187  db_append_string(&sql2, ")");
188  G_debug(3, "IL_check_at_points_2d: %s", db_get_string(&sql2));
189
193  G_fatal_error("Cannot insert new row: %s",
194  db_get_string(&sql2));
195  }
196  count++;
197  }
198  } /* cv */
199
200
201  return 1;
202 }
int IL_check_at_points_2d(struct interp_params *params, struct quaddata *data, double *b, double *ertot, double zmin, double dnorm, struct triple skip_point)
Definition: point2d.c:53
void void void void G_fatal_error(const char *,...) __attribute__((format(printf
interp_fn * interp
Definition: interpf.h:101
double y_orig
dbString sql2
char * db_get_string(const dbString *)
Get string.
Definition: string.c:140
char * table
Name of DB table.
Definition: dig_structs.h:155
double z
int count
double y_orig
Definition: interpf.h:87
#define NULL
Definition: ccmath.h:32
double x_orig
#define GV_POINT
Feature types used in memory on run time (may change)
Definition: dig_defines.h:182
struct triple * points
SYMBOL * err(FILE *fp, SYMBOL *s, char *msg)
FILE * fddevi
Definition: interpf.h:95
dbDriver * driver2
int db_append_string(dbString *, const char *)
Append string to dbString.
Definition: string.c:205
double b
Definition: r_raster.c:39
int db_close_database(dbDriver *)
Close database connection.
Definition: c_closedb.c:26
int db_execute_immediate(dbDriver *, dbString *)
Execute SQL statements.
Definition: c_execute.c:27
struct field_info * ff
off_t Vect_write_line(struct Map_info *, int, const struct line_pnts *, const struct line_cats *)
Writes a new feature.
int Vect_append_point(struct line_pnts *, double, double, double)
Appends one point to the end of a line.
Definition: line.c:149
double x
int db_shutdown_driver(dbDriver *)
Closedown the driver, and free the driver structure.
Definition: shutdown.c:36
void db_zero_string(dbString *)
Zero string.
Definition: string.c:79
double fi
Definition: interpf.h:80
int Vect_reset_cats(struct line_cats *)
Reset category structure to make sure cats structure is clean to be re-used.
double x_orig
Definition: interpf.h:87
double ymax
double xmax
struct line_pnts * Pnts
int G_debug(int, const char *,...) __attribute__((format(printf
double y