CosmoCoffee Forum Index CosmoCoffee

 
 FAQFAQ   SearchSearch  MemberlistSmartFeed   MemberlistMemberlist    RegisterRegister 
   ProfileProfile   Log inLog in 
Arxiv New Filter | Bookmarks & clubs | Arxiv ref/author:

CosmoMC: action = 2 vs action = 4
 
Post new topic   Reply to topic    CosmoCoffee Forum Index -> Computers and software
View previous topic :: View next topic  
Author Message
Erick Almaraz



Joined: 10 Jun 2012
Posts: 25
Affiliation: University of Mexico

PostPosted: October 28 2016  Reply with quote

Hi everybody. I have run CosmoMC setting action = 2 to find the best-fit point. The minimum output file lists, besides the best fit values of all the parameters, the information about the total chi-sq and the chi-sq for every data set I used:

Code:
 -log(Like)   chi-sq    data
      7.527    15.053   CMB: lowl = commander_rc2_v1.1_l2_29_B
    380.793    761.585   CMB: plik = plik_dx11dr2_HM_v18_TT
    347.808    695.616   SN: JLA December_2013
      0.008      0.016   BAO: 6DF
      0.704      1.407   BAO: MGS
      1.102      2.204   BAO: DR11CMASS
      0.155      0.310   BAO: DR11LOWZ


Then I fixed the central values of the parameters in the ini file to the best fit values quoted in the minimum file and now use action = 4 to calculate the likelihood for this particular choice. I suppose the results of the chi-sq should be very similar. However, I get:

Code:
    loglike     chi-sq
      7.550     15.100   CMB: lowl = commander_rc2_v1.1_l2_29_B
    451.099    902.198   CMB: plik = plik_dx11dr2_HM_v18_TT
    347.818    695.636   SN: JLA December_2013
      0.008      0.016   BAO: 6DF
      0.704      1.407   BAO: MGS
      1.102      2.204   BAO: DR11CMASS
      0.155      0.310   BAO: DR11LOWZ

As can be seen, the results for CMB-lowl, SNe and BAO are very similar, but the results for CMB-highl are very different. Does anybody knows what's going on?

Regards
Back to top
View user's profile [ Hidden ]
Antony Lewis



Joined: 23 Sep 2004
Posts: 1301
Affiliation: University of Sussex

PostPosted: October 28 2016  Reply with quote

Look like a small shift in amplitude (or possibly theta) - check your output parameters are the same to enough decimal places?
Back to top
View user's profile [ Hidden ] Visit poster's website
Erick Almaraz



Joined: 10 Jun 2012
Posts: 25
Affiliation: University of Mexico

PostPosted: October 28 2016  Reply with quote

Dear Antony. Thanks for the quick reply. I noticed that I only fixed the usual cosmological parameters (eg, omegabh2, omegach2, etc), but I omitted to fix also the Planck's hard parameters (eg, calPlanck, kgal100, etc). After doing that, the results from action = 2 and action = 4 are the same!

Regards.
Back to top
View user's profile [ Hidden ]
Display posts from previous:   
Post new topic   Reply to topic    CosmoCoffee Forum Index -> Computers and software All times are GMT + 5 Hours
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


Powered by phpBB © 2001, 2005 phpBB Group. Sponsored by WordWeb online dictionary and dictionary software.