// C program for calculating shape of a flower with the use of Cardioid (a_independent_angle), Sep. 25, 2012
// file name: flower_a_independent_angle.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
double xx[30001],yy[30001];// Take care of the upper limit of storage memory capacitance.
double p;// the index of overlap of petals
double dp;// increment of "p"
double beta;// an arbitral width of phase angle with which each petal contacts to the center circle
double dbeta;// increment of "beta"
float l;// the correction factor for "beta" ( 0 < l )
int m;// counting number of "dbeta"
int nf;// devision number of "f" and "beta"
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("Input the correction factor for 'beta'. \n l= ? ( 0 < l )");
scanf("%f",&l);
printf("l=%f\n",l);
beta=alpha;// fundamental equivalence
beta=l*beta;// corrected width of phase angle with which each petal contacts to the center circle
tmin=-pi/2;
tmax=3*pi/2;
nf=200;
dt=(tmax-tmin)/nf;// plotting interval of phase angle "t" before conversion
dbeta=beta/nf;// increment of beta
dp=2*pi/n/20;// increment of p
// execution of calculation
i=0;
for(j=1;j<=n;j++) // sweep of n numbers of petals
{
m=0;
for(t=tmin;t<=tmax+dt;t=t+dt) // sweep of phase angle "t" of the each petal
{
i++;
m++;
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=-alpha*z/pi+pi/2+2*pi*(j-1)/n;
xx[i]=r*cos(f)+c*cos(2*pi*(j-1)/n+pi/2-beta/2+m*dbeta);
yy[i]=r*sin(f)+c*sin(2*pi*(j-1)/n+pi/2-beta/2+m*dbeta);
printf("i=%d,x=%f,y=%f\n",i,xx[i],yy[i]);
}
if(l<1) // connecting by an arc curve to fill a gap between adjacent petals (start)
{
for(p=2*pi*(j-1)/n+beta/2;p< 2*pi*j/n-beta/2+dp;p=p+dp)
{
i++;
xx[i]=c*cos(p+pi/2);
yy[i]=c*sin(p+pi/2);
printf("i=%d,x=%f,y=%f\n",i,xx[i],yy[i]);
}
}
else
{
for(p=2*pi*(j-1)/n+beta/2;p>2*pi*j/n-beta/2+dp;p=p-dp)
{
i++;
xx[i]=c*cos(p+pi/2);
yy[i]=c*sin(p+pi/2);
printf("i=%d,x=%f,y=%f\n",i,xx[i],yy[i]);
}
} // connecting by an arc curve to fill a gap between adjacent petals (the end)
}
imax=i;
xx[imax+1]=xx[1];
yy[imax+1]=yy[1];
// writing the calculated coordinates data of the curve into a textfile
fp=fopen("flower_a_independent_angle.txt","w");
if(fp==NULL)
{
printf("FILE OPEN ERROR\n");
}
else
{
// for(i=1;i<=imax;i++)
for(i=1;i<=imax+1;i++)
{
fprintf(fp,"%f,%f\n",xx[i],yy[i]);
}
fflush(fp);
fclose(fp);
}
printf("end\n");
}// the end of the program
RETURN