Accessing derived parameters in Cobaya from modified CLASS

[kmsurrao]

Hi, I'm running into issues with accessing derived parameters in cobaya using a modified version of CLASS. I think the problem is coming from Line 725 (get_can_provide_params) in classy.py, where the derived parameters one can access is hard-coded

cobaya/cobaya/theories/classy/classy.py

Line 726 in c50acea

names = ["h", "H0", "Omega_Lambda", "Omega_cdm", "Omega_b", "Omega_m", "Omega_k",

.

[jcolinhill]

Just to explain this further, the error message that arises is:

[model] ERROR Could not find whom to assign output parameters ['log10f_scf', 'log10m_scf'].

(These are derived parameters computed in our modified version of CLASS.) @cmbant do we need to modify the Cobaya source to access these derived parameters? This seems like a change w.r.t. older versions of Cobaya, where I did not run into this issue. Thanks-

[cmbant]

I guess so, don't know if there's a way to introspect them - classy is not my domain!

[jcolinhill]

Is the implementation different somehow for doing the same thing on a modified version of CAMB? (It seems somewhat less hard-coded:

cobaya/cobaya/theories/camb/camb.py

Line 793 in c50acea

def get_can_provide_params(self):

)

[cmbant]

for camb get_can_provide_params introspects most of them from the camb source.