3-d plot demo

 #pragma _ipath "./"
 #include "plcdemos.h"
 
 #define XPTS   35		/* Data points in x */
 #define YPTS   46		/* Data points in y */
 
 static PLFLT alt[] = {60.0, 20.0};
 static PLFLT az[] = {30.0, 60.0};
 static void cmap1_init(int);
 
 static char *title[] =
 {
     "#frPLplot Example 8 - Alt=60, Az=30",
     "#frPLplot Example 8 - Alt=20, Az=60",
 };
 
 
 static void
 cmap1_init(int gray)
 {
   PLFLT i[2], h[2], l[2], s[2];
 
   i[0] = 0.0;		  i[1] = 1.0;		
   if (gray) {
     h[0] = 0.0;		    h[1] = 0.0;		
     l[0] = 0.5;		    l[1] = 1.0;		
     s[0] = 0.0;		    s[1] = 0.0;		  } else {
     h[0] = 240;    h[1] = 0;
     l[0] = 0.6;
     l[1] = 0.6;
 
     s[0] = 0.8;
     s[1] = 0.8;
   }
 
   plscmap1n(256);
   plscmap1l(0, 2, i, h, l, s, NULL);
 }
 
 
 
 static int sombrero;
 
 #define LEVELS 10
 
 int
 main(int argc, char *argv[])
 {
   int i, j, k;
   PLFLT *x, *y, **z;
   PLFLT xx, yy, r;
   PLINT ifshade;
   PLFLT zmin, zmax, step;
   PLFLT clevel[LEVELS];
   PLINT nlevel=LEVELS;
   int   rosen=1;
 
   (void) plParseOpts(&argc, argv, PL_PARSE_FULL);
   if (sombrero)
     rosen=0;
 
 
   plinit();
 
 
   x = (PLFLT *) calloc(XPTS, sizeof(PLFLT));
   y = (PLFLT *) calloc(YPTS, sizeof(PLFLT));
 
   plAlloc2dGrid(&z, XPTS, YPTS);
 
   for (i = 0; i < XPTS; i++) {
     x[i] = ((double) (i - (XPTS / 2)) / (double) (XPTS / 2));
     if (rosen)
       x[i] *=  1.5;
   }
 
   for (i = 0; i < YPTS; i++) {
     y[i] = (double) (i - (YPTS / 2)) / (double) (YPTS / 2);
     if (rosen)
       y[i] += 0.5;
   }
 
   for (i = 0; i < XPTS; i++) {
     xx = x[i];
     for (j = 0; j < YPTS; j++) {
       yy = y[j];
       if (rosen) {
 	z[i][j] = pow(1. - xx, 2.) + 100. * pow(yy - pow(xx, 2.), 2.);
 		if (z[i][j] > 0.)
 	  z[i][j] = log(z[i][j]);
 	else
 	  z[i][j] = -5.;      }
       else {
 	r = sqrt(xx * xx + yy * yy);
 	z[i][j] = exp(-r * r) * cos(2.0 * PI * r);
       }
     }
   }
 
   plMinMax2dGrid(z, XPTS, YPTS, &zmax, &zmin);
   step = (zmax-zmin)/(nlevel+1);
   for (i=0; i<nlevel; i++)
     clevel[i] = zmin + step + step*i;
 
   pllightsource(1.,1.,1.);
 
   for (k = 0; k < 2; k++) {
     for (ifshade = 0; ifshade < 4; ifshade++) {
       pladv(0);
       plvpor(0.0, 1.0, 0.0, 0.9);
       plwind(-1.0, 1.0, -0.9, 1.1);
       plcol0(3);
       plmtex("t", 1.0, 0.5, 0.5, title[k]);
       plcol0(1);
       if (rosen)
 	plw3d(1.0, 1.0, 1.0, -1.5, 1.5, -0.5, 1.5, zmin, zmax, alt[k], az[k]);
       else
 	plw3d(1.0, 1.0, 1.0, -1.0, 1.0, -1.0, 1.0, zmin, zmax, alt[k], az[k]);
 
       plbox3("bnstu", "x axis", 0.0, 0,
 	     "bnstu", "y axis", 0.0, 0,
 	     "bcdmnstuv", "z axis", 0.0, 0);
       plcol0(2);
 
       if (ifshade == 0) {	cmap1_init(1);
 	plsurf3d(x, y, z, XPTS, YPTS, 0, NULL, 0);
       } else if (ifshade == 1) {	cmap1_init(0);
 	plsurf3d(x, y, z, XPTS, YPTS, MAG_COLOR, NULL, 0);
       } else if (ifshade == 2) {	plsurf3d(x, y, z, XPTS, YPTS, MAG_COLOR |
 ++++FACETED, NULL, 0);
       } else	plsurf3d(x, y, z, XPTS, YPTS, MAG_COLOR | SURF_CONT | BASE_CONT,
 ++++clevel, nlevel);
     }
   }
 
 
   free((void *) x);
   free((void *) y);
   plFree2dGrid(z, XPTS, YPTS);
 
   plend();
 
   exit(0);
 }