CosmoMC: drawing samples according to a MVNormal distribution

Use of Healpix, camb, CLASS, cosmomc, compilers, etc.
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gongbo zhao
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Joined: January 04 2005
Affiliation: ICG, Portsmouth
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CosmoMC: drawing samples according to a MVNormal distributio

Post by gongbo zhao » September 26 2016

Dear Antony and all,

Suppose I want to draw samples for a set of parameters which obey a given multivariate Gaussian distribution, is it easy to hack CosmoMC to do this? I see there is a patch for this purpose for early cosmomc versions (https://sites.google.com/site/adambmant ... rs#version), and I am wondering if it is easier to do it with new versions? It would be great if you could help with instructions.

Many thanks,
GB

Antony Lewis
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Joined: September 23 2004
Affiliation: University of Sussex
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Re: CosmoMC: drawing samples according to a MVNormal distrib

Post by Antony Lewis » September 27 2016

You can set 'test_likelihood=T. This will use as a likelihood your prior bounds and a Gaussian given by the covariance matrix (propose matrix) supplied.

Or you can use generic_mcmc=T and write your own in Generic_GetLogLikeMain.

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