// Calculation Program for displaying five egg curves 3 (Suugaku-Dokusyuu-Juku's), 17(Thurs.) Sep., 2009



// file name: egg_shaped_curve_SUUDUKU_2b.c



// recommended values: a=1.5, b=1.2, c=8;



#include< stdio.h>

#include< math.h>



void main(void)

{

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

	int i,imax,n,nmax,j,m;

	double xmax,dx;

	double xx[2005],yy[10][1005];// Take care of the upper limit of storage memory capacitance.



	FILE *fp;



// Setting of the constants

    a=1.5;b=1.2;c=8;

	 

// Setting of the other parameters

	xmax=a;// the maximum value of x

	dx=xmax/250;// the plotting interval of x



	db=b/12;

	bmax=b+2*db+0.00001;

	bmin=b-2*db;



// execution of calculation

	i=0;

	for(x=-xmax;x<=xmax+dx/10;x=x+dx)

	{

		i++;

		n=0;

		xx[i]=x;



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

		{

			n++;



         	        if(x>xmax)

                 	{

                		y=0;

                 	}

                	else

                	{

                		y=(1+(x+a)/c)*sqrt(1-(x/a)*(x/a))/b;

                	}



			yy[n][i]=y;



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

		}

	}

	imax=i;



	nmax=n;

	j=0;



	for(i=imax+1;i<=2*imax;i++)

	{

		j++;

		m=imax-j;



		xx[i]=xx[m];



		for(n=1;n<=nmax;++n)

		{

			yy[n][i]=-yy[n][m];

		}

	}



// 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<2*imax;i++)

		{

			fprintf(fp,"%f,%f,%f,%f,%f,%f\n",xx[i],yy[1][i],yy[2][i],yy[3][i],yy[4][i],yy[5][i]);

		}

		fflush(fp);

		fclose(fp);

	}

	printf("end\n");

}// the end of the program