I am working with the CosmoMC Oct 2009 release with a modified version of CAMB to include a different routine for generating the primordial power spectrum. (I have extensively tested the functioning of CAMB alone, and it produces output in line with what I expect, based on reproducing earlier results.)
After altering CAMB, I altered settings.f90, params_CMB.f90, params.ini and params_CMB.paramnames in the source directory in order to account for the difference in the parametrization of the primordial power spectrum of my model compared to the standard LCDM. (My parametrization does not require normalization parameters logA and r, however for the sake of convenience I have left them in the params.ini file with fixed values rather than alter the code to avoid problems with norm_freq_ix etc.) I am using WMAP5 data only, without tensors. The total number of parameters I am varying is 7 (3 fast).
As this is the first run of the altered code I do not have a proposal matrix, so I have set propose_matrix empty and estimate_propose_matrix = T.
The code then attempts to find the max-like point and goes through a few iterations of determining the gradient with respect different elements before giving the error message:
I have followed through the code and it appears this error message is being generated because the program ends up in subroutine OutOfBounds, because the parameter asz acquires a value that is outside the min-max range set in params.ini (it gets larger than 2 as well as smaller than 0). All other parameters are at values I would have expected.ERROR: Trial parameters excluded by prior or error in likelihood
Try starting further away from problem regions?
Can anyone please explain how to get around this problem? I have left the start value, maximum, minimum etc. for asz exactly as they were in the downloaded version of CosmoMC.