1 // array.cxx -- Array management class
3 // Written by Curtis Olson, started March 1998.
5 // Copyright (C) 1998 - 1999 Curtis L. Olson - curt@flightgear.org
7 // This program is free software; you can redistribute it and/or
8 // modify it under the terms of the GNU General Public License as
9 // published by the Free Software Foundation; either version 2 of the
10 // License, or (at your option) any later version.
12 // This program is distributed in the hope that it will be useful, but
13 // WITHOUT ANY WARRANTY; without even the implied warranty of
14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 // General Public License for more details.
17 // You should have received a copy of the GNU General Public License
18 // along with this program; if not, write to the Free Software
19 // Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
22 // (Log is kept at end of this file)
29 #include <Include/compiler.h>
31 // #include <ctype.h> // isspace()
32 // #include <stdlib.h> // atoi()
33 // #include <math.h> // rint()
35 // #include <string.h>
36 // #ifdef HAVE_SYS_STAT_H
37 // # include <sys/stat.h> // stat()
39 // #ifdef FG_HAVE_STD_INCLUDES
42 // # include <errno.h>
44 // #ifdef HAVE_UNISTD_H
45 // # include <unistd.h> // stat()
50 #include <Include/fg_constants.h>
51 #include <Misc/fgstream.hxx>
52 #include <Misc/strutils.hxx>
53 #include <Math/leastsqs.hxx>
60 FGArray::FGArray( void ) {
61 // cout << "class FGArray CONstructor called." << endl;
62 in_data = new float[ARRAY_SIZE_1][ARRAY_SIZE_1];
63 out_data = new float[ARRAY_SIZE_1][ARRAY_SIZE_1];
67 FGArray::FGArray( const string &file ) {
68 // cout << "class FGArray CONstructor called." << endl;
69 in_data = new float[ARRAY_SIZE_1][ARRAY_SIZE_1];
70 out_data = new float[ARRAY_SIZE_1][ARRAY_SIZE_1];
78 FGArray::open( const string& file ) {
79 // open input file (or read from stdin)
81 cout << " Opening array data pipe from stdin" << endl;
83 // fd = gzdopen(STDIN_FILENO, "r");
84 cout << " Not yet ported ..." << endl;
87 in = new fg_gzifstream( file );
89 cout << " Cannot open " << file << endl;
92 cout << " Opening array data file: " << file << endl;
99 // close an Array file
102 // the fg_gzifstream doesn't seem to have a close()
117 *in >> originx >> originy;
118 *in >> cols >> col_step;
119 *in >> rows >> row_step;
121 cout << " origin = " << originx << " " << originy << endl;
122 cout << " cols = " << cols << " rows = " << rows << endl;
123 cout << " col_step = " << col_step << " row_step = " << row_step <<endl;
125 for ( int i = 0; i < cols; i++ ) {
126 for ( int j = 0; j < rows; j++ ) {
127 *in >> in_data[i][j];
131 cout << " Done parsing\n";
137 // Initialize output mesh structure
138 void FGArray::outputmesh_init( void ) {
141 for ( j = 0; j < ARRAY_SIZE_1; j++ ) {
142 for ( i = 0; i < ARRAY_SIZE_1; i++ ) {
143 out_data[i][j] = -9999.0;
149 // Get the value of a mesh node
150 double FGArray::outputmesh_get_pt( int i, int j ) {
151 return ( out_data[i][j] );
155 // Set the value of a mesh node
156 void FGArray::outputmesh_set_pt( int i, int j, double value ) {
157 // cout << "Setting data[" << i << "][" << j << "] = " << value << endl;
158 out_data[i][j] = value;
162 // Use least squares to fit a simpler data set to dem data
163 void FGArray::fit( double error ) {
164 double x[ARRAY_SIZE_1], y[ARRAY_SIZE_1];
165 double m, b, max_error, error_sq;
169 int n, row, start, end;
170 int colmin, colmax, rowmin, rowmax;
172 // FILE *dem, *fit, *fit1;
174 error_sq = error * error;
176 cout << " Initializing output mesh structure" << endl;
179 // determine dimensions
184 cout << " Fitting region = " << colmin << "," << rowmin << " to "
185 << colmax << "," << rowmax << endl;;
187 // include the corners explicitly
188 outputmesh_set_pt(colmin, rowmin, in_data[colmin][rowmin]);
189 outputmesh_set_pt(colmin, rowmax, in_data[colmin][rowmax]);
190 outputmesh_set_pt(colmax, rowmax, in_data[colmax][rowmax]);
191 outputmesh_set_pt(colmax, rowmin, in_data[colmax][rowmin]);
193 cout << " Beginning best fit procedure" << endl;
195 for ( row = rowmin; row < rowmax; row++ ) {
196 // fit = fopen("fit.dat", "w");
197 // fit1 = fopen("fit1.dat", "w");
201 // cout << " fitting row = " << row << endl;
203 while ( start < colmax - 1 ) {
207 x[0] = start * col_step;
208 y[0] = in_data[start][row];
210 x[1] = end * col_step;
211 y[1] = in_data[end][row];
215 // cout << "Least square of first 2 points" << endl;
216 least_squares(x, y, n, &m, &b);
220 while ( (end < colmax) && good_fit ) {
222 // cout << "Least square of first " << n << " points" << endl;
223 x[n-1] = x1 = end * col_step;
224 y[n-1] = y1 = in_data[end][row];
225 least_squares_update(x1, y1, &m, &b);
226 // ave_error = least_squares_error(x, y, n, m, b);
227 max_error = least_squares_max_error(x, y, n, m, b);
230 printf("%d - %d ave error = %.2f max error = %.2f y = %.2f*x + %.2f\n",
231 start, end, ave_error, max_error, m, b);
233 f = fopen("gnuplot.dat", "w");
234 for ( j = 0; j <= end; j++) {
235 fprintf(f, "%.2f %.2f\n", 0.0 + ( j * col_step ),
238 for ( j = start; j <= end; j++) {
239 fprintf(f, "%.2f %.2f\n", 0.0 + ( j * col_step ),
244 printf("Please hit return: "); gets(junk);
247 if ( max_error > error_sq ) {
255 // error exceeded the threshold, back up
256 end -= 2; // back "end" up to the last good enough fit
257 n--; // back "n" up appropriately too
259 // we popped out of the above loop while still within
260 // the error threshold, so we must be at the end of
265 least_squares(x, y, n, &m, &b);
266 // ave_error = least_squares_error(x, y, n, m, b);
267 max_error = least_squares_max_error(x, y, n, m, b);
271 printf("%d - %d ave error = %.2f max error = %.2f y = %.2f*x + %.2f\n",
272 start, end, ave_error, max_error, m, b);
275 fprintf(fit1, "%.2f %.2f\n", x[0], m * x[0] + b);
276 fprintf(fit1, "%.2f %.2f\n", x[end-start], m * x[end-start] + b);
279 if ( start > colmin ) {
280 // skip this for the first line segment
282 outputmesh_set_pt(start, row, (lasty + cury) / 2);
283 // fprintf(fit, "%.2f %.2f\n", x[0], (lasty + cury) / 2);
286 lasty = m * x[end-start] + b;
294 dem = fopen("gnuplot.dat", "w");
295 for ( j = 0; j < ARRAY_SIZE_1; j++) {
296 fprintf(dem, "%.2f %.2f\n", 0.0 + ( j * col_step ),
302 // NOTICE, this is for testing only. This instance of
303 // output_nodes should be removed. It should be called only
304 // once at the end once all the nodes have been generated.
305 // newmesh_output_nodes(&nm, "mesh.node");
306 // printf("Please hit return: "); gets(junk);
309 // outputmesh_output_nodes(fg_root, p);
313 // return the current altitude based on grid data. We should rewrite
314 // this to interpolate exact values, but for now this is good enough
315 double FGArray::interpolate_altitude( double lon, double lat ) {
316 // we expect incoming (lon,lat) to be in arcsec for now
318 double xlocal, ylocal, dx, dy, zA, zB, elev;
319 int x1, x2, x3, y1, y2, y3;
323 /* determine if we are in the lower triangle or the upper triangle
331 then calculate our end points
334 xlocal = (lon - originx) / col_step;
335 ylocal = (lat - originy) / row_step;
337 xindex = (int)(xlocal);
338 yindex = (int)(ylocal);
340 // printf("xindex = %d yindex = %d\n", xindex, yindex);
342 if ( xindex + 1 == cols ) {
346 if ( yindex + 1 == rows ) {
350 if ( (xindex < 0) || (xindex + 1 >= cols) ||
351 (yindex < 0) || (yindex + 1 >= rows) ) {
352 cout << "WARNING: Attempt to interpolate value outside of array!!!"
357 dx = xlocal - xindex;
358 dy = ylocal - yindex;
362 // printf(" Lower triangle\n");
366 z1 = in_data[x1][y1];
370 z2 = in_data[x2][y2];
374 z3 = in_data[x3][y3];
376 // printf(" dx = %.2f dy = %.2f\n", dx, dy);
377 // printf(" (x1,y1,z1) = (%d,%d,%d)\n", x1, y1, z1);
378 // printf(" (x2,y2,z2) = (%d,%d,%d)\n", x2, y2, z2);
379 // printf(" (x3,y3,z3) = (%d,%d,%d)\n", x3, y3, z3);
381 zA = dx * (z2 - z1) + z1;
382 zB = dx * (z3 - z1) + z1;
384 // printf(" zA = %.2f zB = %.2f\n", zA, zB);
386 if ( dx > FG_EPSILON ) {
387 elev = dy * (zB - zA) / dx + zA;
393 // printf(" Upper triangle\n");
397 z1 = in_data[x1][y1];
401 z2 = in_data[x2][y2];
405 z3 = in_data[x3][y3];
407 // printf(" dx = %.2f dy = %.2f\n", dx, dy);
408 // printf(" (x1,y1,z1) = (%d,%d,%d)\n", x1, y1, z1);
409 // printf(" (x2,y2,z2) = (%d,%d,%d)\n", x2, y2, z2);
410 // printf(" (x3,y3,z3) = (%d,%d,%d)\n", x3, y3, z3);
412 zA = dy * (z2 - z1) + z1;
413 zB = dy * (z3 - z1) + z1;
415 // printf(" zA = %.2f zB = %.2f\n", zA, zB );
416 // printf(" xB - xA = %.2f\n", col_step * dy / row_step);
418 if ( dy > FG_EPSILON ) {
419 elev = dx * (zB - zA) / dy + zA;
430 // Write out a node file that can be used by the "triangle" program.
431 // Check for an optional "index.node.ex" file in case there is a .poly
432 // file to go along with this node file. Include these nodes first
433 // since they are referenced by position from the .poly file.
434 void FGArray::outputmesh_output_nodes( const string& fg_root, FGBucket& p )
436 double exnodes[MAX_EX_NODES][3];
437 struct stat stat_buf;
439 char file[256], exfile[256];
446 int colmin, colmax, rowmin, rowmax;
447 int i, j, count, excount, result;
449 // determine dimensions
450 colmin = p.get_x() * ( (cols - 1) / 8);
451 colmax = colmin + ( (cols - 1) / 8);
452 rowmin = p.get_y() * ( (rows - 1) / 8);
453 rowmax = rowmin + ( (rows - 1) / 8);
454 cout << " dumping region = " << colmin << "," << rowmin << " to " <<
455 colmax << "," << rowmax << "\n";
457 // generate the base directory
458 string base_path = p.gen_base_path();
459 cout << " fg_root = " << fg_root << " Base Path = " << base_path << endl;
460 dir = fg_root + "/Scenery/" + base_path;
461 cout << " Dir = " << dir << endl;
463 // stat() directory and create if needed
465 result = stat(dir.c_str(), &stat_buf);
466 if ( result != 0 && errno == ENOENT ) {
467 cout << " Creating directory\n";
469 command = "mkdir -p " + dir + "\n";
470 system( command.c_str() );
472 // assume directory exists
475 // get index and generate output file name
476 index = p.gen_index();
477 sprintf(file, "%s/%ld.node", dir.c_str(), index);
479 // get (optional) extra node file name (in case there is matching
481 strcpy(exfile, file);
482 strcat(exfile, ".ex");
484 // load extra nodes if they exist
486 if ( (fd = fopen(exfile, "r")) != NULL ) {
488 fscanf(fd, "%d %d %d %d", &excount, &junki, &junki, &junki);
490 if ( excount > MAX_EX_NODES - 1 ) {
491 printf("Error, too many 'extra' nodes, increase array size\n");
494 printf(" Expecting %d 'extra' nodes\n", excount);
497 for ( i = 1; i <= excount; i++ ) {
498 fscanf(fd, "%d %lf %lf %lf\n", &junki,
499 &exnodes[i][0], &exnodes[i][1], &exnodes[i][2]);
500 printf("(extra) %d %.2f %.2f %.2f\n",
501 i, exnodes[i][0], exnodes[i][1], exnodes[i][2]);
506 printf("Creating node file: %s\n", file);
507 fd = fopen(file, "w");
509 // first count regular nodes to generate header
511 for ( j = rowmin; j <= rowmax; j++ ) {
512 for ( i = colmin; i <= colmax; i++ ) {
513 if ( out_data[i][j] > -9000.0 ) {
517 // printf(" count = %d\n", count);
519 fprintf(fd, "%d 2 1 0\n", count + excount);
521 // now write out extra node data
522 for ( i = 1; i <= excount; i++ ) {
523 fprintf(fd, "%d %.2f %.2f %.2f\n",
524 i, exnodes[i][0], exnodes[i][1], exnodes[i][2]);
527 // write out actual node data
529 for ( j = rowmin; j <= rowmax; j++ ) {
530 for ( i = colmin; i <= colmax; i++ ) {
531 if ( out_data[i][j] > -9000.0 ) {
532 fprintf(fd, "%d %.2f %.2f %.2f\n",
534 originx + (double)i * col_step,
535 originy + (double)j * row_step,
539 // printf(" count = %d\n", count);
547 FGArray::~FGArray( void ) {
548 // printf("class FGArray DEstructor called.\n");
555 // Revision 1.2 1999/03/13 23:50:26 curt
556 // Tweaked output formatting a bit.
558 // Revision 1.1 1999/03/13 18:45:02 curt
559 // Initial revision. (derived from libDEM.a code.)