M-filter

Updates filters. Goal here: ensure filter is sane and documented, then merge to make it available.

cpp/kspace.cpp

@@ -330,43 +330,6 @@ void kspace<be, dt>::ball_filter(
                 });
 }
 
-/** \brief Filter a field using a M-filter to reproduce dissipation range.
- *
- *  Filter's  Fourier space expression:
- *  \f[
- *       \hat{\phi^M_\ell}(k) =
- *       \exp(-\frac{(3.54 k \ell)^{122 \ell^{0.0836}}}{2})
- *       \left( 1 + \frac{(k \eta/0.0636)^{3.44}}{1 + (k \eta/ 0.0621)^{3.44}} \right)^{1/2}
- *  \f]
- */
-template <field_backend be,
-          kspace_dealias_type dt>
-template <typename rnumber,
-          field_components fc>
-void kspace<be, dt>::general_M_filter(
-        typename fftw_interface<rnumber>::complex *__restrict__ a,
-        const double ell)
-{
-    const double prefactor0 = 1.0;
-    this->CLOOP_K2(
-            [&](const ptrdiff_t cindex,
-                const ptrdiff_t xindex,
-                const ptrdiff_t yindex,
-                const ptrdiff_t zindex,
-                const double k2){
-                if (k2 > 0)
-                {
-                    const double argument = std::sqrt(k2)*ell;
-                    const double prefactor = prefactor0;
-                    for (unsigned int tcounter=0; tcounter<2*ncomp(fc); tcounter++)
-                        ((rnumber*)a)[2*ncomp(fc)*cindex + tcounter] *= (
-//                            prefactor * (std::exp(-0.5*std::pow((2.9*argument),(68.0*(std::pow(ell,0.74))))) * std::sqrt(1.0 + (std::pow((argument/0.06),3.8))/(1.0 + (std::pow((argument/0.057),3.8))))));
-                            prefactor * (std::exp(-1.7*argument)) * std::sqrt(1.0 + 0.68*(std::pow((argument/0.065),4.6))/(1.0 + (std::pow((argument/0.065),4.6)))));
-                }
-                });
-}
-
-
 /** \brief Filter a field using a Gaussian kernel.
  *
  * \tparam rnumber type of real number, float or double.
@@ -472,12 +435,6 @@ int kspace<be, dt>::filter(
                 a,
                 2*acos(0.)/wavenumber);
     }
-    else if (filter_type == std::string("general_M"))
-    {
-        this->template general_M_filter<rnumber, fc>(
-                a,
-                2*acos(0.)/wavenumber);
-    }
     return EXIT_SUCCESS;
 }
 
@@ -561,12 +518,6 @@ int kspace<be, dt>::filter_calibrated_ell(
                 a,
                 ell);
     }
-    else if (filter_type == std::string("general_M"))
-    {
-        this->template general_M_filter<rnumber, fc>(
-                a,
-                ell);
-    }
     return EXIT_SUCCESS;
 }