CosmoMC using Planck l > ~200 only

Use of Healpix, camb, CLASS, cosmomc, compilers, etc.
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Elizabeth Gould
Posts: 13
Joined: January 30 2015
Affiliation: Queen's University

CosmoMC using Planck l > ~200 only

Post by Elizabeth Gould » February 14 2018

I would like to match a model to the Planck data for only the ls greater than a specific number. While I know how to create an effective cutoff for high ls within CosmoMC, I don't see a way to only match the model to the higher l values. I remember one post indicating that to do this, one must remove the data from the dataset, but the Planck data is not stored in an easy to alter way. I was wondering if anyone knew how to do this, either in the CosomMC code or the Planck dataset.

Sofie Marie Koksbang
Posts: 10
Joined: February 27 2017
Affiliation: University of Helsinki

Re: CosmoMC using Planck l > ~200 only

Post by Sofie Marie Koksbang » September 24 2018


In case you are still interested:

You can change the l interval by using the tool "clik_change_lrange" as described in the readme file of plc-2.0, i.e. you cd to ..../plc-2.0/src/python/tools and type "python ..../plc_2.0/hi_l/plik/name_of_existing_TT_or_TTEEE.clik lmin lmax .../plc_2.0/hi_l/plik/the_name_you_want_the_new_datafile_to_have".

In the above, 1) "...." is the path to you plc directories, and 2) lmin and lmax are the numbers you want for the minimum and maximum l-values considered so in the case where one wants to consider l>200 you type 200 in the place of lmin and -1 in the place of lmax (-1 means that you don't want to change the maximum l-value).

Remember also to change the name of the data files you want CosmoMC to use in the .ini-files in batch2. I expect the names of these files depend on which version of CosmoMC you are using, but they are called something along the lines of plik_dx11dr2_HM_v18_TT(TTEEE).ini. In these, you change the file name in the line starting with "clik_data_plik = " (so e.g. find the correct files by typing grep 'clik_dat_plik' * in you terminal when cd's to the batch2 directory).

- Sofie

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