Dakota Reference Manual: chain_samples

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chain_samples

Number of Markov Chain Monte Carlo posterior samples

## Specification

Alias: samples

Argument(s): INTEGER

Default: method-dependent

## Description

The `chain_samples` keyword indicates the number of draws from the posterior distribution to perform. When an emulator is active, this will be the number of samples on the constructed surrogate model.

Default Behavior

The default number of chain samples is method-dependent. QUESO and MUQ methods use 1000. DREAM uses (number of generations) x (number of chains), resulting in chain_samples close to that specified.

Usage Tips

MCMC methods typically require a large number of chain samples to converge, often thousands to millions.

## Examples

    method
      bayes_calibration queso
        chain_samples = 20000