code: def createMCMC(config,srcfile,section='source',samples=None):
      
  
      source = ugali.analysis.source.Source()
      source.load(srcfile,section=section)
      loglike = ugali.analysis.loglike.createLoglike(config,source)
  
      mcmc = MCMC(config,loglike)
      if samples is not None:
          mcmc.load_samples(samples)
  
      return mcmc
docs: Create an MCMC instance