When running cosmomc by adding additional parameters other than base LambdaCDM model, I constantly run into the error:
MCMC.f90: Couldn't start after 1000 tries - check starting ranges
For example, I run 10 chains with
param[mnu] = 0.06 0 5 0.2 0.03
param[w] = −1 −3.5 −0.5 1.0 0.1
param[nnu] = 3.046 0.05 10.0 2.0 0.15
and PlanckTTTEEE+lowTEB+lensing+BAO data without propose matrix it reports this error. This happens even if I add parameter nnu only. The range above is not much different from the paper of Planck Collaboration (e.g. Table 1 in 1303.5076). I noticed the webpage of cosmomc reads
and tried to adjust both the start_width and propose_width but it didn't work. Any advice on how to choose the width or how this error can be solved?The propose_width should be of the order of the conditional posterior width (i.e. the expected error in that parameter when other parameters are fixed).