update in the M-filter

cpp/kspace.cpp

@@ -311,7 +311,8 @@ void kspace<be, dt>::general_M_filter(
                     double prefactor = prefactor0;
                     for (unsigned int tcounter=0; tcounter<2*ncomp(fc); tcounter++)
                         ((rnumber*)a)[2*ncomp(fc)*cindex + tcounter] *= (
-                            prefactor * (exp(-0.5*pow((2.9*argument),(68.0*(pow(ell,0.74))))) * sqrt(1.0 + (pow((argument/0.06),3.8))/(1.0 + (pow((argument/0.057),3.8))))));
+//                            prefactor * (exp(-0.5*pow((2.9*argument),(68.0*(pow(ell,0.74))))) * sqrt(1.0 + (pow((argument/0.06),3.8))/(1.0 + (pow((argument/0.057),3.8))))));
+                            prefactor * (exp(-1.7*argument)) * sqrt(1.0 + 0.68*(pow((argument/0.065),4.6))/(1.0 + (pow((argument/0.065),4.6)))));
                 }
                 });
 }