### Planck 2015 likelihood: Extracting covariance

Posted:

**January 16 2018**Hello everyone,

So I've spent the last few days trying to work out how to use the code supplied in plc_2.0 (COM_Likelihood_Code...) in the Planck 2015 Likelihood code with the plik data to construct a data covariance matrix. This is including the off-diagonal components due to multipole mixing as well.

Does anyone have any idea where to start? I've been looking at cliklike.F90 in the CosmoMC code (most recent version) as well, but there doesn't seem to be any clear links. I've only seen covariance codes set up for the foreground routines, in the cmb_only component of the code and as I say I don't really understand how to use it.

To be clear: trying to create a covariance matrix between the Cls including binned-ls and the mixing between different multipoles.

I've been looking at the clik header files and the computational aspects included in clik_compute but I cannot find the routines where the covariance is calculated??

Please any help would be appreciated :)

Thanks

Luke

So I've spent the last few days trying to work out how to use the code supplied in plc_2.0 (COM_Likelihood_Code...) in the Planck 2015 Likelihood code with the plik data to construct a data covariance matrix. This is including the off-diagonal components due to multipole mixing as well.

Does anyone have any idea where to start? I've been looking at cliklike.F90 in the CosmoMC code (most recent version) as well, but there doesn't seem to be any clear links. I've only seen covariance codes set up for the foreground routines, in the cmb_only component of the code and as I say I don't really understand how to use it.

To be clear: trying to create a covariance matrix between the Cls including binned-ls and the mixing between different multipoles.

I've been looking at the clik header files and the computational aspects included in clik_compute but I cannot find the routines where the covariance is calculated??

Please any help would be appreciated :)

Thanks

Luke