/* Demonstration of 3-d plotting */

#include <math.h>
      
#define   NPTS   41

static int opt[] = {1,   2,   3,   3};

static float alt[] = {60.0,20.0,60.0,60.0};

static float az[] = {30.0,60.0,120.0,160.0};

static char *title[4] =  {
   "\\frPLPLOT Example 8 - Alt=60, Az=30, Opt=1",
   "\\frPLPLOT Example 8 - Alt=20, Az=60, Opt=2",
   "\\frPLPLOT Example 8 - Alt=60, Az=120, Opt=3",
   "\\frPLPLOT Example 8 - Alt=60, Az=160, Opt=3"
};

main()
{
   int i, j, k;

   float x[NPTS], y[NPTS], z[NPTS][NPTS];
   float xx, yy, r;
   int work[4*NPTS];

   for (i=0; i<NPTS; i++)  {
      x[i] = (i-(NPTS/2))/(double)(NPTS/2);
      y[i] = (i-(NPTS/2))/(double)(NPTS/2);
   }

   for (i=0; i<NPTS; i++)  {
      xx = x[i];
      for (j=0; j<NPTS; j++)  {
         yy = y[j];
         r = sqrt(xx*xx + yy*yy);
         z[i][j] = exp(-r*r) * cos(2.0*3.141592654*r);
      }
   }

   plstar(1,1);

   for (k=0; k<4; k++)  {
      pladv(0);
      plvpor(0.0,1.0,0.0,0.9);
      plwind(-1.0,1.0,-0.9,1.1);

      plw3d(1.0,1.0,1.0,-1.0,1.0,-1.0,1.0,-1.0,1.0,alt[k],az[k]);
      plbox3("bnstu","x axis",0.0,0,"bnstu","y axis",0.0,0,
             "bcmnstuv","z axis",0.0,0);
      plot3d(x,y,z,work,NPTS,NPTS,NPTS,opt[k]);
      if(k==1 || k==3)
         plside3(x,y,z,NPTS,NPTS,NPTS,opt[k]);
      if(k==2 || k==3)
         plgrid3(0.0);
      plmtex("t",1.0,0.5,0.5,title[k]);
   }

   pltext();
   plend();
}