docs: def raw_separation(self,mag_1,mag_2,steps=10000):
          """ 
          Calculate the separation in magnitude-magnitude space between points and isochrone. Uses a dense sampling of the isochrone and calculates the metric distance from any isochrone sample point.
  
          Parameters:
          -----------
          mag_1 : The magnitude of the test points in the first band
          mag_2 : The magnitude of the test points in the second band
          steps : Number of steps to sample the isochrone
  
          Returns:
          --------
          sep : Minimum separation between test points and isochrone sample
          """
       
          # http://stackoverflow.com/q/12653120/
          mag_1 = np.array(mag_1,copy=False,ndmin=1)
          mag_2 = np.array(mag_2,copy=False,ndmin=1)
       
          init,pdf,act,iso_mag_1,iso_mag_2 = self.sample(mass_steps=steps)
          iso_mag_1+=self.distance_modulus
          iso_mag_2+=self.distance_modulus
       
          iso_cut = (iso_mag_1<np.max(mag_1))&(iso_mag_1>np.min(mag_1)) | \
                    (iso_mag_2<np.max(mag_2))&(iso_mag_2>np.min(mag_2))
          iso_mag_1 = iso_mag_1[iso_cut]
          iso_mag_2 = iso_mag_2[iso_cut]
           
          dist_mag_1 = mag_1[:,np.newaxis]-iso_mag_1
          dist_mag_2 = mag_2[:,np.newaxis]-iso_mag_2
          
          return np.min(np.sqrt(dist_mag_1**2 + dist_mag_2**2),axis=1)