const int xcor = 100000;

double DD[xcor];
double RR[xcor];
double DR[xcor];
int cDD[xcor];
int cRR[xcor];
int cDR[xcor];
double ds = 0.01; // 1 Mpc
double cf[xcor];
double s[xcor];
const int kbins = 200; 
double kbinwd = 20./kbins;