Fixed possible crash with silly V

infer.cc

@@ -27,6 +27,7 @@ Infer::Infer(float udLh, float ut, unsigned int uV) {
   dLh = udLh;
   t = ut;
   V = uV;
+  if (V<=0.0) V=1.0;
 
   if (fabs(t)<13.0) {
     Em_ = V * pow(2*M_PI,-2) * dLh * (sqr(t) - 1) * exp(-sqr(t)/2.0);