BayesicFitting

Model Fitting and Evidence Calculation

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class Explorer( object )Source

Explorer is a helper class of NestedSampler, which contains and runs the diffusion engines.

It uses Threads to parallelise the diffusion engines.

Attributes

  • walkers : WalkerList
         walkers to be explored
  • engines : [engine]
         list of engines to be used
  • errdis : ErrorDistribution
         to be used
  • rng : numpy.random.RandomState
         random number generator
  • rate : float (1.0)
         governs processing speed (vs precision)
  • maxtrials : int (5)
         number of trials
  • verbose : int (0)
         level of blabbering
  • lowLhood : float
         present low likelihood level
  • iteration : int
         counting explorer calls

Author Do Kester.

Explorer( ns, threads=False )

Construct Explorer from a NestedSampler object.

Parameters

  • ns : NestedSampler
         the calling NestedSampler. It provides the attributes.

explore( worst, lowLhood, iteration )
Explore the likelihood function, using threads.

Parameters

  • worst : [int]
         list of walkers to be explored/updated
  • lowLhood : float
         level of the low likelihood

exploreWalker( kw, lowLhood, engines, rng )
Move the walker around until it is randomly distributed over the prior and higher in logL then lowLhood

Parameters

  • kw : int
         index in walkerlist, of the walker to be explored
  • lowLhood : float
         minimum value for the log likelihood
  • engine : list of Engine
         to be used
  • rng : RandomState
         random number generator

selEngines( iteration )
Select engines with slowly changing parameters once per so many iterations.

Parameter

  • iteration : int
         iteration number

allEngines( iteration )
Always use all engines.

Parameters

  • iteration : int
         iteration number

checkWalkers( )

Perform logLcheck() on all walkers.

logLcheck( walker )
Sanity check when no moves are found, if the LogL is still the same as the stored logL.

Parameters

  • walker : Walker
         the one with the stored logL

Raises

ValueError at inconsistency.