//  Calculation Program for displaying four egg curves. (egg shaped curve V), 05 (Thurs.) Nov., 2009



// file name: egg5a2.c



#include< stdio.h>

#include< math.h>



void main(void)

{

	double x,y,a,b,c,db,bmax,bmin,pai;

	double t,dt;

	int i,imax,n,nmax;

	double xx[10001],yy[10][10001];// Take care of the upper limit of storage memory capacitance.



	FILE *fp;



// Setting of the constants

	pai=3.1415927;

    a=1;

	bmax=0.9;

	bmin=0.3;

	c=0.1;

	db=0.2;



	printf("a=%f\n\n",a);

	 

// Setting of the other parameter

	dt=pai/1000;// plotting interval of the phase angle



// execution of calculation

	i=0;

	for(t=-2*pai;t<=2*pai;t=t+dt)

	{

		i++;

		n=0;



		for(b=bmin;b<=bmax+db/100;b=b+db)

		{

			n++;

			x=a*cos(t);

	    	y=(b+c*cos(t))*sin(t);

			yy[n][i]=y;

			xx[i]=x;

			printf("i=%d,x=%f,y=%f\n",i,x,y);

		}

	}

	imax=i;

	nmax=n;



// writing the calculated coordinates data of the curve into a textfile

	fp=fopen("egg-shaped curve.txt","w");

	if(fp==NULL)

		{

		printf("FILE OPEN ERROR\n");

		}

	else

		{

		for(i=1;i<=imax;i++)

			{

			fprintf(fp,"%f,%f,%f,%f,%f\n",xx[i],yy[1][i],yy[2][i],yy[3][i],yy[4][i]);

			}

		fflush(fp);

		fclose(fp);

		}

	printf("end\n");

}// the end of the program