search

OliverFHD / CosMomentum

Python and C++ tools to compute the PDF and moments of the cosmic density field.
GNU General Public License v2.0
5 stars 6 forks source link

Polynomial order of fits to the cumulant generating function. #15

Closed OliverFHD closed 4 years ago

OliverFHD commented 4 years ago

When fitting the cumulant generating function with polynomials of very high order in tau (order = 19) , the inverse Laplace transform can get stuck in the high density tail.

OliverFHD commented 4 years ago

This problem goes away once phi(tau) is expressed as

phi(tau) = lambda(tau)*dphi/dlambda(tau) - 0.5 tau^2 .

This is because the polynomial coefficients of dphi/dlambda(tau) can be fit much more robustly (than those of phi(tau)).