CosmoMC: Finding the best fit Log likelihood
Posted: October 26 2005
Dear all:
I want to find the best fit -Log(Like) value of a given cosmological model using some datasets.I set action = 2 in params.ini since MCMC cannot provide accurate best fit values. Testing with \Lambda CDM model using WMAP-only data , I found the same result using two different initial seeds as follows:
Random seeds: 4321, 9373 rand_inst: 0
Random seeds: 12345, 9373 rand_inst: 0
Computing tensors: F
Doing CMB lensing: F
lmax = 2100
Number of C_ls = 3
Varying 6 parameters ( 2 fast)
reading: params_CMB.covmat
Finding max-like point
reading WMAP data
WMAP read
Change in F is less than 0.10000000 after 4 iterations
Found minimum value of -Log(Like) = 717.2668
Converged sucessfully (loglike changes by less than 0.1000000 )
after 4 iterations
Best fit parameters values:
1 : 2.3866521E-02
2 : 0.1122643
3 : 1.049735
4 : 0.1119891
8 : 0.9966581
11 : 3.118499
Have estimated the minimum, now exiting since action=2
Wrote the minimum to file chains/test2.minimum
I used all the default setting in params.ini except
action=2
delta_loglike = 0.1
use_CMB = T
use_HST = F
use_mpk = F
use_clusters = F
use_BBN = F
use_Age_Tophat_Prior = F
use_SN = F
use_min_zre = 0
The best-fit -Log(Like)=717.2668 is larger than the other published fitting results ( around 714 ),I have tested by setting delta_loglike = 1,2 ,the best-fit -Log(Like) got larger. Did I make any mistakes ? Any comments and suggestion on that ?
Thanks in advance .
Cheers
Gongbo Zhao
I want to find the best fit -Log(Like) value of a given cosmological model using some datasets.I set action = 2 in params.ini since MCMC cannot provide accurate best fit values. Testing with \Lambda CDM model using WMAP-only data , I found the same result using two different initial seeds as follows:
Random seeds: 4321, 9373 rand_inst: 0
Random seeds: 12345, 9373 rand_inst: 0
Computing tensors: F
Doing CMB lensing: F
lmax = 2100
Number of C_ls = 3
Varying 6 parameters ( 2 fast)
reading: params_CMB.covmat
Finding max-like point
reading WMAP data
WMAP read
Change in F is less than 0.10000000 after 4 iterations
Found minimum value of -Log(Like) = 717.2668
Converged sucessfully (loglike changes by less than 0.1000000 )
after 4 iterations
Best fit parameters values:
1 : 2.3866521E-02
2 : 0.1122643
3 : 1.049735
4 : 0.1119891
8 : 0.9966581
11 : 3.118499
Have estimated the minimum, now exiting since action=2
Wrote the minimum to file chains/test2.minimum
I used all the default setting in params.ini except
action=2
delta_loglike = 0.1
use_CMB = T
use_HST = F
use_mpk = F
use_clusters = F
use_BBN = F
use_Age_Tophat_Prior = F
use_SN = F
use_min_zre = 0
The best-fit -Log(Like)=717.2668 is larger than the other published fitting results ( around 714 ),I have tested by setting delta_loglike = 1,2 ,the best-fit -Log(Like) got larger. Did I make any mistakes ? Any comments and suggestion on that ?
Thanks in advance .
Cheers
Gongbo Zhao