﻿ C_program_sigle_egg_curve_etc.(Suugaku-Dokusyuu-Juku's)
```

//  Calculation Program for displaying a single egg curve etc.
// (by Mr. Yasuyuki ASAI {Suugaku-Dokusyuu-Juku's]), 30(Thurs.)
// July, 2009

// in the case that a=1, c=2.9

// file name: egg_shaped_curve_SUUDOKU.c

#include< stdio.h>

#include< math.h>

void main(void)

{

double x,y,a,c,pai;

double t,dt;

int i,imax;

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

FILE *fp;

// Setting of the constants

pai=3.1415927;

a=1;

c=2.9;
// a circle for c=1, a crecent for 0 < c <1, a round fan
// for 1 < c < 2, and an egg for c > 2

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

// Setting of the other parameters

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

// execution of calculation

i=0;

for(t=0;t<=2*pai+0.001;t=t+dt)

{

i++;

x=a*((c-2)*cos(t)+c+2)*(cos(t)+1)/4;

y=a*sin(t);

yy[i]=y;

xx[i]=x;

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

}

imax=i;

// 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\n",xx[i],yy[i]);

}

fflush(fp);

fclose(fp);

}

printf("end\n");

}// the end of the program

```

RETURN