#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include "pssub.h"

void xaxis(double,double,double,double,int,int);

void main()
{   
     init();
     viewport(0.2, 0.2, 0.8, 0.8); 
     xyworld(-1.2, -1.2, 1.2, 1.2); 
     xaxis(-1.0,0.0,1.0,0.0,2,10);
     fin();
}

void xaxis(double x1,double y1,double x2,double y2,int m,int n)
{
     int i;double s,d,x,dx,dy;
     setgray(0.0);
     s=(x2-x1)*(x2-x1)+(y2-y1)*(y2-y1);s=sqrt(s);
     d=s/(double)60;
     arrow(x1-s/20.0, y1, x2+s/20.0*2.0, y2, d);
     for (i=0;i<=m*n;i++){
        x=1.0/(double)(m*n)*(double)i; if(i/n*n==i) dy=0.02; else  dy=0.01; 
        line( -x, -dy, -x, dy); 
        line( x, -dy, x, dy);
        } stroke();
     textx(x2+s/10.0*2.0, -s/30.0,"x");
     textx((x1+x2)/2.0,(y1+y2)/2.0,"O");
     textx(x2/2.0,y2,"pi/2");
     textx(x2,y2,"pi");
     textx(x1/2.0,y1,"-pi/2");
     textx(x1,y1,"-pi");
     stroke();
     return;
}