float gasdev(void)
{
/* float ran3(long *idum); */
static int iset=0;
static float gset;
float fac, rsq, v1, v2, temp;
/* We don't have an extra deviate handy, so pick 2 uniform numbers in
the square extending from -1 to +1 in each direction, see if they
are in the unit circle, and if they are not, try again.*/
if (iset == 0){
do{
v1 = 2.0*rand0to1()-1.0;
v2 = 2.0*rand0to1()-1.0;
rsq=v1*v1+v2*v2;
}while (rsq >= 1.0 ||rsq == 0.0);
temp = -2.0*log(rsq)/rsq;
if (temp >= 0.0) fac = sqrt(temp);
else {
printf("error in gasdev\n");
}
/* Now make the Box-Muller transformation to get 2 normal deviates.
Return one and save the other for the next time. */
gset = v1*fac;
iset=1; /*set flag */
return v2*fac;
} else{
/* We have an extra deviate handy, so unset the flag, and return it.*/
iset = 0;
return gset;
}
}
/* Create an array of random integers between the range [min,max) */
int * randintarray(const int size,const int Min,const int max){
int i, * array;
array = (int *) malloc(size*sizeof(int));
for(i=0;i<size;i++)
array[i] = Min + floor((double)max*rand0to1());
return array;
}
int rand_in_rad(const float rad, float *x, float *y){
int found=0;
float tx,ty;
do{
tx = 2 * rad * (rand0to1()-0.5);
ty = 2 * rad * (rand0to1()-0.5);
if( rad > sqrt( pow(tx,2) + pow(ty,2) ) ){
found = 1;
}
}while(!found);
*x = tx;
*y = ty;
return 0;
}
/* Create an array of random integers between the range [min,max) */
int * randboolarray(const int size){
int i, * array;
float v;
array = (int *) malloc(size*sizeof(int));
for(i=0;i<size;i++){
v=rand0to1();
if(v<0.5)
array[i] = 0;
else
array[i] = 1;
}
return array;
}
