Pie chart demo

 #pragma _ipath "./"
 #include "plcdemos.h"
 
 static char *text[] =
 {
     "Maurice",
     "Geoffrey",
     "Alan",
     "Rafael",
     "Vince"
 };
 
 
 int
 main(int argc, char *argv[])
 {
     int i, j, dthet, theta0, theta1, theta;
     PLFLT just, dx, dy;
     static PLFLT x[500], y[500], per[5];
 
     per[0] = 10.;
     per[1] = 32.;
     per[2] = 12.;
     per[3] = 30.;
     per[4] = 16.;
 
 
     (void) plParseOpts(&argc, argv, PL_PARSE_FULL);
 
 
     plinit();
 
     plenv(0., 10., 0., 10., 1, -2);
     plcol0(2);
     theta0 = 0;
     dthet = 1;
     for (i = 0; i <= 4; i++) {
 	j = 0;
 	x[j] = 5.;
 	y[j++] = 5.;
 	theta1 = theta0 + 5 * per[i];
 	if (i == 4)
 	    theta1 = 500;
 	for (theta = theta0; theta <= theta1; theta += dthet) {
 	    x[j] = 5 + 3 * cos((2.*PI/500.)*theta);
 	    y[j++] = 5 + 3 * sin((2.*PI/500.)*theta);
 	}
 	plcol0(i + 1);
 	plpsty((i + 3) % 8 + 1);
 	plfill(j, x, y);
 	plcol0(1);
 	plline(j, x, y);
 	just = (2.*PI/500.)*(theta0 + theta1)/2.;
 	dx = .25 * cos(just);
 	dy = .25 * sin(just);
 	if ((theta0 + theta1)  < 250 || (theta0 + theta1) > 750) 
 	    just = 0.;
 	else 
 	    just = 1.;
 
 	plptex((x[j / 2] + dx), (y[j / 2] + dy), 1.0, 0.0, just, text[i]);
 	theta0 = theta - dthet;
     }
     plfont(2);
     plschr(0., 1.3);
     plptex(5.0, 9.0, 1.0, 0.0, 0.5, "Percentage of Sales");
 
 
     plend();
     exit(0);
 }