#include <stdio.h>
#include <stdlib.h>
#include <math.h>
static const int N=32;
typedef struct
{
float r[N][3]; //position
float v[N][3]; //velocity
}Particle;
float sq(float a)
{
return a*a;
}
void init_r(Particle *p)
{
int i,j;
float r2;
for(i=0;i<N;){
p->r[i][0]=2*drand48()-1.0;
p->r[i][1]=2*drand48()-1.0;
p->r[i][2]=2*drand48()-1.0;
r2=sqrt(sq(p->r[i][0]) + sq(p->r[i][1]) + sq(p->r[i][2]));
p->v[i][0]=0.0;
p->v[i][1]=0.0;
p->v[i][2]=0.0;
if (r2 <= 1.0) i++;
}
}
int main(int argc,char** argv)
{
int i;
Particle p;
init_r(&p);
for(i=0;i<N;i++)
{
printf("%f,%f,%f \n",p.r[i][0],p.r[i][1],p.r[i][2]);
}
return 0;
}