MCMC.f90 couldn't start with BAO Likelihood

Use of Cobaya. camb, CLASS, cosmomc, compilers, etc.
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Alessandro Di Marco
Posts: 15
Joined: April 01 2015
Affiliation: University of Rome - Tor Vergata

MCMC.f90 couldn''t start with BAO Likelihood

Post by Alessandro Di Marco » April 16 2015

Dear Antony,
I have the following problem with CosmoMc:
when I fix some parameters such as ch2 or bh2 in test.ini file, CosmoMc works without any problems.
But when I try to effectuate a running, fixing these parameters with BAO likelihood, CosmoMc crashes with the following error:


"MCMC.f90 couldn't start after 1000 tries - check starting ranges"

With SNLs likelihood, for example, I have not problem!
Could you help me?
Thanks a lot in advance!

Antony Lewis
Posts: 1941
Joined: September 23 2004
Affiliation: University of Sussex
Contact:

Re: MCMC.f90 couldn''''t start with BAO Likelihood

Post by Antony Lewis » April 17 2015

Please give the exact change in your .ini file.

Alessandro Di Marco
Posts: 15
Joined: April 01 2015
Affiliation: University of Rome - Tor Vergata

MCMC.f90 couldn''t start with BAO Likelihood

Post by Alessandro Di Marco » April 17 2015

This is the structure of my test.ini file.
I have fixed few parameters and when I turn on SNLS.ini CosmoMc does not crash.
This problems appears with BAO Likelihood.

DEFAULT(batch1/CAMspec_defaults.ini)
DEFAULT(batch1/lowLike.ini)
DEFAULT(batch1/lowl.ini)


#cmb_dataset[BICEP2]=data/BICEP/BICEP2.dataset
#for r>0 also need compute_tensors=T:
compute_tensors = T

#planck lensing
#DEFAULT(batch1/lensing.ini)

#Other Likelihoods
DEFAULT(batch1/BAODR11.ini)
#DEFAULT(batch1/HST.ini)
#DEFAULT(batch1/Union.ini)
#DEFAULT(batch1/SNLS.ini)
#DEFAULT(batch1/WiggleZ_MPK.ini)
#DEFAULT(batch1/MPK.ini)

#general settings
DEFAULT(batch1/common_batch1.ini)

#high for new runs
MPI_Max_R_ProposeUpdate = 30

#propose_matrix= planck_covmats/base_w_planck_lowl_lowLike_BAO.covmat

#Folder where files (chains, checkpoints, etc.) are stored
root_dir = chains/

#Root name for files produced
file_root=test1
#action= 0 runs chains, 1 importance samples, 2 minimizes
#use action=4 just to quickly test likelihoods
action = 0

#if you want to get theory cl for test point
#test_output_root = output_cl_root

start_at_bestfit = F
feedback=1
use_fast_slow = T

#sampling_method=7 is a new fast-slow scheme good for Planck
sampling_method = 7
dragging_steps = 3
propose_scale = 2

#Set >0 to make data files for importance sampling
indep_sample=0

#these are just small speedups for testing
get_sigma8=F

#Uncomment this if you don't want one 0.06eV neutrino by default
#num_massive_neutrinos=
#to vary parameters set param[name]= center, min, max, start width, propose width
param[omegabh2] = 0.0221
param[omegach2] = 0.12
param[theta] = 1.0411
param[w] = -1

#for PICO install from https://pypi.python.org/pypi/pypico and download data file
#cosmology_calculator=PICO
#pico_datafile = pico3_tailmonty_v34.dat
#pico_verbose=F


Thank you Antony!

Antony Lewis
Posts: 1941
Joined: September 23 2004
Affiliation: University of Sussex
Contact:

Re: MCMC.f90 couldn''''t start with BAO Likelihood

Post by Antony Lewis » April 17 2015

Perhaps those fixed values give a background cosmology with BAO likelihoods outside the range supported by the BAO likelihood interpolation files? You can run with action=4 as a quick test.

Alessandro Di Marco
Posts: 15
Joined: April 01 2015
Affiliation: University of Rome - Tor Vergata

MCMC.f90 couldn''t start with BAO Likelihood

Post by Alessandro Di Marco » April 18 2015

I have tried to do various runnings excluding cold dark matter and in these cases CosmoMc operats smoothly.
So there is a compatibility range problem, maybe, as you say!

Thank you again for the suggestion and support Antony!

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