Cosmomc : How to get matter transfer functions ?

[charles jose]

Hi All

I would like to know how to get matter transfer function from cosmomc ? When I run camb alone I can get transfer function by setting "get_transfer = T" in the params.ini file.
But when I run cosmomc the transfer functions are not printed even if I set "get_transfer = T" in the params.ini of camb.

Basically I need matter transfer functions for each set of parameters explored by cosmomc. So even the name of variables storing k values as well as transfer functions will be useful.

Hope my question is clear. Looking forward to an answer !

Thanks you very much
Charles

[Xin Wang]

Hi All

I would like to know how to get matter transfer function from cosmomc ? When I run camb alone I can get transfer function by setting "get_transfer = T" in the params.ini file.
But when I run cosmomc the transfer functions are not printed even if I set "get_transfer = T" in the params.ini of camb.

Basically I need matter transfer functions for each set of parameters explored by cosmomc. So even the name of variables storing k values as well as transfer functions will be useful.

Hope my question is clear. Looking forward to an answer !

Thanks you very much
Charles

Hi, Charles,

I don't think the params.ini file of CAMB is even used when running cosmomc. The matter power spectra data are stored in Theory%matter_power(k,z) quantity, where max of k is num_matter_power and max of z is matter_power_lnzsteps and both of them are specified in cmbtypes.f90. You can output this quantity, however an issue you have to keep an eye on is that the matter power spectra are calculated many times approximately close to the value of samples in the params.ini file of cosmomc. It may be a little difficult to re-arrange the matter power data to match specific parameter values used in the calculation. If you succeed in doing that, I would very much love to learn from you!

best regards,
Xin

[Xin Wang]

Hi All

I would like to know how to get matter transfer function from cosmomc ? When I run camb alone I can get transfer function by setting "get_transfer = T" in the params.ini file.
But when I run cosmomc the transfer functions are not printed even if I set "get_transfer = T" in the params.ini of camb.

Basically I need matter transfer functions for each set of parameters explored by cosmomc. So even the name of variables storing k values as well as transfer functions will be useful.

Hope my question is clear. Looking forward to an answer !

Thanks you very much
Charles

Sorry, I just find out that you're asking for outputting transfer function data. It should be a little more difficult than outputting the matter power spectra data, but it's definitely doable. Please confer module lrggettheory.f90. I think the quantity you're looking for is MTrans%TransferData

[charles jose]

Thank you very much Xin

Charles