beginning to fold in HOD code with jeremy tinker's approval

c_tools/hod/chi2_dist.c

@@ -0,0 +1,44 @@
+#include <math.h>
+#include <stdlib.h>
+#include <stdio.h>
+
+#define pi 3.14159265358979323846
+
+double nu;
+double func(double);
+double func_gam(double);
+double func_gauss(double);
+
+int main(int argc, char **argv)
+{
+  int i,n;
+  double x,f,qromo(),midinf(),fgam,midpnt(),fgauss;
+  
+  nu=2;
+  if(argc>1)
+    nu=atof(argv[1]);
+
+  fgam = qromo(func_gam,0.0,0.1,midpnt) + qromo(func_gam,0.1,1.0E+30,midinf);
+
+  for(i=1;i<=200;++i)
+    {
+      x=i/10.0;
+      f=qromo(func,x,1.0E+30,midinf);
+      fgauss = 2*qromo(func_gauss,0.0,x,midpnt);
+      f*=1/(pow(2.0,nu/2.0)*fgam);
+      printf("%f %e %e\n",x,1-f,fgauss);
+    }
+}
+
+double func(double x)
+{
+  return(pow(x,nu/2-1)*exp(-x/2));
+}
+double func_gam(double x)
+{
+  return(pow(x,nu/2-1)*exp(-x));
+}
+double func_gauss(double x)
+{
+  return(exp(-x*x/2)/sqrt(2*pi));
+}