Dear All
I've installed Cosmomc in my computer. In the final steps of the instalation, I had to do:
1)>./camb params.ini – and results are:
Age of universe/Gyr = 13,592
…...........................................
Doing the above command, I didn't get any error.
But, when I write
.>cosmomc params.ini
or
.>cosmomc params.ini 1
Random seeds: 23978, 26009 rand_inst: 0
Computing tensors: F
Doing CMB lensing: T
lmax = 2100
Number of C_ls = 3
Varying 7 parameters ( 0 fast)
reading: params_CMB.covmat
starting MonteCarlo
reading WMAP5 data
Initializing WMAP likelihood, version v3
^Cforrtl: error (69): process interrupted (SIGINT)
Image PC Routine Line Source
. FFFFE424 Unknown Unknown Unknown
libguide.so 4008D16E Unknown Unknown Unknown
libpthread.so.0 400A9315 Unknown Unknown Unknown
libc.so.6 40C6BDDE Unknown Unknown Unknown
So, I used the suggestion in cosmomcofee.info/viewtopic.php?t=1074, i.e. , ulimit s unlimited and the program starts run and show the following
Initializing WMAP likelihood, version v3
0 rat: 0.4807692 in 104 (M) best: 1330.946
0 rat: 0.4464286 in 224 (M) best: 1329.457
0 rat: 0.4261364 in 352 (M) best: 1329.457
0 rat: 0.4149378 in 482 (M) best: 1329.457
0 rat: 0.4045307 in 618 (M) best: 1329.457
0 rat: 0.3947369 in 760 (M) best: 1329.441
0 rat: 0.3950339 in 886 (M) best: 1329.441
0 rat: 0.3875969 in 1032 (M) best: 1329.441
…..............................
Is this normal?
I would like to Know the amount of time required to run the algorithm?
Best Regards
Bruna
Cosmomc Instalation and Running

 Posts: 3
 Joined: February 10 2009
 Affiliation: Centro Astrofisica UP

 Posts: 1
 Joined: May 30 2008
 Affiliation: ICG Portsmouth
Cosmomc Instalation and Running
Seems that you have managed to install cosmomc. The output is the normal one. Typically with a good proposal matrix the acceptance ratio is about 0.3 (i.e. the mean multiplicity is about 3). The resulting chain(s) is in cosmomc/chains. You can analyse the results with getdist. Remember to cut out the burnin period.
How long you need to run depends on your problem. For the adiabatic LambdaCDM with the supplied proposal matrix *.covmat maybe less than one day is enough. For "new models" for which you don't have a good proposal matrix to start with, you may need couple of weeks of initial runs (and playing with your guessed propose widths and the MC temperature) before you obtain a good proposal matrix. Then the final run may take couple of days (or even weeks) on a super computer, and you should create several chains, since the MCMC is a probabilistic thing.
How long you need to run depends on your problem. For the adiabatic LambdaCDM with the supplied proposal matrix *.covmat maybe less than one day is enough. For "new models" for which you don't have a good proposal matrix to start with, you may need couple of weeks of initial runs (and playing with your guessed propose widths and the MC temperature) before you obtain a good proposal matrix. Then the final run may take couple of days (or even weeks) on a super computer, and you should create several chains, since the MCMC is a probabilistic thing.