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[CAMB/CosmoMC] Reusing generated Cls in CosmoMC

Posted: June 11 2018
by Luke Hart
Within CAMB, the CMB power spectrum is generated and outputted to file. Similarly, the CMB power spectra are communicated to CosmoMC when used in conjunction with a likelihood. Is there a way to import Cls to bypass the whole CAMB calculation step when trying to deduce the likelihood for a given set of theory Cls?

Re: [CAMB/CosmoMC] Reusing generated Cls in CosmoMC

Posted: June 12 2018
by Antony Lewis
If you've run a chain and produced .data files, you can importance sample quickly by reading cls from the data files. But there's no specific built-in function to read cls from any other external file.

[CAMB/CosmoMC] Reusing generated Cls in CosmoMC

Posted: June 12 2018
by Luke Hart
I appreciate you Antony and others are quite busy, but would you have any idea how one would go about this?? I have had a look at the GeneralSetup.F90 file as well as the driver file, the CosmoTheory.f90 file etc. and I know it will probably be just a small co-ordination of the parameter references to the file read options, so I'm sort of at a loss.

If we get this working, I have some other code that if refined, could be a nice addition to the standard CosmoMC code.