// C program for calculating shape of a flower (a_overlap). Sep. 19, 2012
// file name: flower_curve_a_overlap.c
#include< stdio.h>
#include< math.h>
void main(void)
{
double a,pi;// "a" is the constant of the original Cardioid, and "pi" is the pi
double t,dt;// the phase angle and its increment of the Cardioid before the conversion respectively
double r,z;// the moving radius and the phase angle of the Cardioid after some conversion respectively
double f;// the phase angle of the Cardioid after the final conversion into a horned one (using as a petal of a flower)
int n;// a desired numbers of petals of a flower
double alpha;// the angle for the horned Cardioid (used as that alpha=2*pi/n )
double tmin,tmax;// the minimum and maximum values of the phase angle "t" respectively
int i,imax,j;
float c;// the radius of a center circle
float p;// the index of overlap of petals
double xx[30001],yy[30001];// Take care of the upper limit of storage memory capacitance.
double ff,fs,dfs,ff0,ffs;// intermediates variables
FILE *fp;
// setting of the constants
pi=3.141592;
a=1.;
// setting of the other parameters
printf("Input a desired numbers of petals of a flower in natural number. \n n=? ");
scanf("%d",&n);
printf("n=%d\n",n);
alpha=2*pi/n;
printf("Input the radius of a center circle. \n c= ? ");
scanf("%f",&c);
printf("c=%f\n",c);
printf("0< p< 1 in the case of no overlap of petals, and 1< p in the case of overlap of petals. \n p= ? ");
scanf("%f",&p);
printf("p=%f\n",p);
tmin=-pi/2;
tmax=3*pi/2;
dt=(tmax-tmin)/500;// plotting interval of the phase angle "t" before conversion
// execution of calculation
i=0;
for(j=1;j<=n;j++)
{
for(t=tmin;t<=tmax+dt;t=t+dt)
{
i++;
if(t>(3*pi/2-dt) && t<(3*pi/2+dt))
{
r=0.;
z=-pi/2;
}
else
{
if(t>(-pi/2-dt) && t<(-pi/2+dt))
{
r=0.;
z=pi/2;
}
else
{
r=a*sqrt((5-3*sin(t))*(1+sin(t)));
z=asin(a*(1-sin(t))*cos(t)/r);
}
}
f=-p*(alpha*z/pi)+pi/2+2*pi*(j-1)/n;
ff=f;
if(fabs(p-1.)>0.00001) // connecting by an arc curve to fill a gap between adjacent petals (start)
{
if(i==1&&j==1)
{
ff0=ff;
}
if(t==tmin&&j>1)
{
if(ffs>ff)
{
dfs=(ffs-ff)/20;
for(fs=ffs;fs>=ff;fs=fs-dfs)
{
xx[i]=c*cos(fs);
yy[i]=c*sin(fs);
i++;
}
}
else
{
dfs=(ff-ffs)/20;
for(fs=ffs;fs<=ff;fs=fs+dfs)
{
xx[i]=c*cos(fs);
yy[i]=c*sin(fs);
i++;
}
}
}
} // connecting by an arc curve to fill a gap between adjacent petals (the end)
ffs=ff;
xx[i]=(r+c)*cos(f);
yy[i]=(r+c)*sin(f);
printf("i=%d,x=%f,y=%f\n",i,xx[i],yy[i]);
}
}
if(fabs(p-1.)>0.00001) // connecting by an arc curve to fill a gap between adjacent petals (start)
{
if(ffs>2*pi)
{
ffs=ffs-2*pi;
}
if(ffs>ff0)
{
dfs=(ffs-ff0)/20;
for(fs=ffs;fs>=ff0;fs=fs-dfs)
{
i++;
xx[i]=c*cos(fs);
yy[i]=c*sin(fs);
}
}
else
{
dfs=(ff0-ffs)/20;
for(fs=ffs;fs<=ff0;fs=fs+dfs)
{
i++;
xx[i]=c*cos(fs);
yy[i]=c*sin(fs);
}
}
} // connecting by an arc curve to fill a gap between adjacent petals (the end)
imax=i;
// writing the calculated coordinates data of the curve into a textfile
fp=fopen("flower_a_overlap.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