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()
113 *in >> originx >> originy;
114 *in >> cols >> col_step;
115 *in >> rows >> row_step;
117 cout << " origin = " << originx << " " << originy << endl;
118 cout << " cols = " << cols << " rows = " << rows << endl;
119 cout << " col_step = " << col_step << " row_step = " << row_step <<endl;
121 for ( int i = 0; i < cols; i++ ) {
122 for ( int j = 0; j < rows; j++ ) {
123 *in >> in_data[i][j];
127 cout << " Done parsing\n";
133 // Initialize output mesh structure
134 void FGArray::outputmesh_init( void ) {
137 for ( j = 0; j < ARRAY_SIZE_1; j++ ) {
138 for ( i = 0; i < ARRAY_SIZE_1; i++ ) {
139 out_data[i][j] = -9999.0;
145 // Get the value of a mesh node
146 double FGArray::outputmesh_get_pt( int i, int j ) {
147 return ( out_data[i][j] );
151 // Set the value of a mesh node
152 void FGArray::outputmesh_set_pt( int i, int j, double value ) {
153 // cout << "Setting data[" << i << "][" << j << "] = " << value << endl;
154 out_data[i][j] = value;
158 // Use least squares to fit a simpler data set to dem data
159 void FGArray::fit( double error ) {
160 double x[ARRAY_SIZE_1], y[ARRAY_SIZE_1];
161 double m, b, max_error, error_sq;
165 int n, row, start, end;
166 int colmin, colmax, rowmin, rowmax;
168 // FILE *dem, *fit, *fit1;
170 error_sq = error * error;
172 cout << " Initializing output mesh structure" << endl;
175 // determine dimensions
180 cout << " Fitting region = " << colmin << "," << rowmin << " to "
181 << colmax << "," << rowmax << endl;;
183 // include the corners explicitly
184 outputmesh_set_pt(colmin, rowmin, in_data[colmin][rowmin]);
185 outputmesh_set_pt(colmin, rowmax, in_data[colmin][rowmax]);
186 outputmesh_set_pt(colmax, rowmax, in_data[colmax][rowmax]);
187 outputmesh_set_pt(colmax, rowmin, in_data[colmax][rowmin]);
189 cout << " Beginning best fit procedure" << endl;
192 for ( row = rowmin; row < rowmax; row++ ) {
193 // fit = fopen("fit.dat", "w");
194 // fit1 = fopen("fit1.dat", "w");
198 // cout << " fitting row = " << row << endl;
200 while ( start < colmax - 1 ) {
204 x[0] = start * col_step;
205 y[0] = in_data[start][row];
207 x[1] = end * col_step;
208 y[1] = in_data[end][row];
212 // cout << "Least square of first 2 points" << endl;
213 least_squares(x, y, n, &m, &b);
217 while ( (end < colmax) && good_fit ) {
219 // cout << "Least square of first " << n << " points" << endl;
220 x[n-1] = x1 = end * col_step;
221 y[n-1] = y1 = in_data[end][row];
222 least_squares_update(x1, y1, &m, &b);
223 // ave_error = least_squares_error(x, y, n, m, b);
224 max_error = least_squares_max_error(x, y, n, m, b);
227 printf("%d - %d ave error = %.2f max error = %.2f y = %.2f*x + %.2f\n",
228 start, end, ave_error, max_error, m, b);
230 f = fopen("gnuplot.dat", "w");
231 for ( j = 0; j <= end; j++) {
232 fprintf(f, "%.2f %.2f\n", 0.0 + ( j * col_step ),
235 for ( j = start; j <= end; j++) {
236 fprintf(f, "%.2f %.2f\n", 0.0 + ( j * col_step ),
241 printf("Please hit return: "); gets(junk);
244 if ( max_error > error_sq ) {
252 // error exceeded the threshold, back up
253 end -= 2; // back "end" up to the last good enough fit
254 n--; // back "n" up appropriately too
256 // we popped out of the above loop while still within
257 // the error threshold, so we must be at the end of
262 least_squares(x, y, n, &m, &b);
263 // ave_error = least_squares_error(x, y, n, m, b);
264 max_error = least_squares_max_error(x, y, n, m, b);
268 printf("%d - %d ave error = %.2f max error = %.2f y = %.2f*x + %.2f\n",
269 start, end, ave_error, max_error, m, b);
272 fprintf(fit1, "%.2f %.2f\n", x[0], m * x[0] + b);
273 fprintf(fit1, "%.2f %.2f\n", x[end-start], m * x[end-start] + b);
276 if ( start > colmin ) {
277 // skip this for the first line segment
279 outputmesh_set_pt(start, row, (lasty + cury) / 2);
280 // fprintf(fit, "%.2f %.2f\n", x[0], (lasty + cury) / 2);
283 lasty = m * x[end-start] + b;
291 dem = fopen("gnuplot.dat", "w");
292 for ( j = 0; j < ARRAY_SIZE_1; j++) {
293 fprintf(dem, "%.2f %.2f\n", 0.0 + ( j * col_step ),
299 // NOTICE, this is for testing only. This instance of
300 // output_nodes should be removed. It should be called only
301 // once at the end once all the nodes have been generated.
302 // newmesh_output_nodes(&nm, "mesh.node");
303 // printf("Please hit return: "); gets(junk);
306 // outputmesh_output_nodes(fg_root, p);
310 // return the current altitude based on grid data. We should rewrite
311 // this to interpolate exact values, but for now this is good enough
312 double FGArray::interpolate_altitude( double lon, double lat ) {
313 // we expect incoming (lon,lat) to be in arcsec for now
315 double xlocal, ylocal, dx, dy, zA, zB, elev;
316 int x1, x2, x3, y1, y2, y3;
320 /* determine if we are in the lower triangle or the upper triangle
328 then calculate our end points
331 xlocal = (lon - originx) / col_step;
332 ylocal = (lat - originy) / row_step;
334 xindex = (int)(xlocal);
335 yindex = (int)(ylocal);
337 // printf("xindex = %d yindex = %d\n", xindex, yindex);
339 if ( xindex + 1 == cols ) {
343 if ( yindex + 1 == rows ) {
347 if ( (xindex < 0) || (xindex + 1 >= cols) ||
348 (yindex < 0) || (yindex + 1 >= rows) ) {
349 cout << "WARNING: Attempt to interpolate value outside of array!!!"
354 dx = xlocal - xindex;
355 dy = ylocal - yindex;
359 // printf(" Lower triangle\n");
363 z1 = in_data[x1][y1];
367 z2 = in_data[x2][y2];
371 z3 = in_data[x3][y3];
373 // printf(" dx = %.2f dy = %.2f\n", dx, dy);
374 // printf(" (x1,y1,z1) = (%d,%d,%d)\n", x1, y1, z1);
375 // printf(" (x2,y2,z2) = (%d,%d,%d)\n", x2, y2, z2);
376 // printf(" (x3,y3,z3) = (%d,%d,%d)\n", x3, y3, z3);
378 zA = dx * (z2 - z1) + z1;
379 zB = dx * (z3 - z1) + z1;
381 // printf(" zA = %.2f zB = %.2f\n", zA, zB);
383 if ( dx > FG_EPSILON ) {
384 elev = dy * (zB - zA) / dx + zA;
390 // printf(" Upper triangle\n");
394 z1 = in_data[x1][y1];
398 z2 = in_data[x2][y2];
402 z3 = in_data[x3][y3];
404 // printf(" dx = %.2f dy = %.2f\n", dx, dy);
405 // printf(" (x1,y1,z1) = (%d,%d,%d)\n", x1, y1, z1);
406 // printf(" (x2,y2,z2) = (%d,%d,%d)\n", x2, y2, z2);
407 // printf(" (x3,y3,z3) = (%d,%d,%d)\n", x3, y3, z3);
409 zA = dy * (z2 - z1) + z1;
410 zB = dy * (z3 - z1) + z1;
412 // printf(" zA = %.2f zB = %.2f\n", zA, zB );
413 // printf(" xB - xA = %.2f\n", col_step * dy / row_step);
415 if ( dy > FG_EPSILON ) {
416 elev = dx * (zB - zA) / dy + zA;
427 // Write out a node file that can be used by the "triangle" program.
428 // Check for an optional "index.node.ex" file in case there is a .poly
429 // file to go along with this node file. Include these nodes first
430 // since they are referenced by position from the .poly file.
431 void FGArray::outputmesh_output_nodes( const string& fg_root, FGBucket& p )
433 double exnodes[MAX_EX_NODES][3];
434 struct stat stat_buf;
436 char file[256], exfile[256];
443 int colmin, colmax, rowmin, rowmax;
444 int i, j, count, excount, result;
446 // determine dimensions
447 colmin = p.get_x() * ( (cols - 1) / 8);
448 colmax = colmin + ( (cols - 1) / 8);
449 rowmin = p.get_y() * ( (rows - 1) / 8);
450 rowmax = rowmin + ( (rows - 1) / 8);
451 cout << " dumping region = " << colmin << "," << rowmin << " to " <<
452 colmax << "," << rowmax << "\n";
454 // generate the base directory
455 string base_path = p.gen_base_path();
456 cout << " fg_root = " << fg_root << " Base Path = " << base_path << endl;
457 dir = fg_root + "/Scenery/" + base_path;
458 cout << " Dir = " << dir << endl;
460 // stat() directory and create if needed
462 result = stat(dir.c_str(), &stat_buf);
463 if ( result != 0 && errno == ENOENT ) {
464 cout << " Creating directory\n";
466 command = "mkdir -p " + dir + "\n";
467 system( command.c_str() );
469 // assume directory exists
472 // get index and generate output file name
473 index = p.gen_index();
474 sprintf(file, "%s/%ld.node", dir.c_str(), index);
476 // get (optional) extra node file name (in case there is matching
478 strcpy(exfile, file);
479 strcat(exfile, ".ex");
481 // load extra nodes if they exist
483 if ( (fd = fopen(exfile, "r")) != NULL ) {
485 fscanf(fd, "%d %d %d %d", &excount, &junki, &junki, &junki);
487 if ( excount > MAX_EX_NODES - 1 ) {
488 printf("Error, too many 'extra' nodes, increase array size\n");
491 printf(" Expecting %d 'extra' nodes\n", excount);
494 for ( i = 1; i <= excount; i++ ) {
495 fscanf(fd, "%d %lf %lf %lf\n", &junki,
496 &exnodes[i][0], &exnodes[i][1], &exnodes[i][2]);
497 printf("(extra) %d %.2f %.2f %.2f\n",
498 i, exnodes[i][0], exnodes[i][1], exnodes[i][2]);
503 printf("Creating node file: %s\n", file);
504 fd = fopen(file, "w");
506 // first count regular nodes to generate header
508 for ( j = rowmin; j <= rowmax; j++ ) {
509 for ( i = colmin; i <= colmax; i++ ) {
510 if ( out_data[i][j] > -9000.0 ) {
514 // printf(" count = %d\n", count);
516 fprintf(fd, "%d 2 1 0\n", count + excount);
518 // now write out extra node data
519 for ( i = 1; i <= excount; i++ ) {
520 fprintf(fd, "%d %.2f %.2f %.2f\n",
521 i, exnodes[i][0], exnodes[i][1], exnodes[i][2]);
524 // write out actual node data
526 for ( j = rowmin; j <= rowmax; j++ ) {
527 for ( i = colmin; i <= colmax; i++ ) {
528 if ( out_data[i][j] > -9000.0 ) {
529 fprintf(fd, "%d %.2f %.2f %.2f\n",
531 originx + (double)i * col_step,
532 originy + (double)j * row_step,
536 // printf(" count = %d\n", count);
544 FGArray::~FGArray( void ) {
545 // printf("class FGArray DEstructor called.\n");
552 // Revision 1.3 1999/03/17 23:48:17 curt
553 // Removed forced -g compile flag.
554 // Fixed a couple compiler warnings.
556 // Revision 1.2 1999/03/13 23:50:26 curt
557 // Tweaked output formatting a bit.
559 // Revision 1.1 1999/03/13 18:45:02 curt
560 // Initial revision. (derived from libDEM.a code.)