11.6.3. Running the estimate, exporting and loading chains, and continuing the calculation

The computation can be performed using the standard estimateParameters method, which automatically saves the chains in their associated files. Although it is generally unnecessary (since saving is done automatically), it is still possible to manually export the results of a chain or reload them later using export_chain_MCMC and read_chain_MCMC, whose prototypes are the following:

# Export one chain
export_chain_MCMC(fileName)
# Read one chain
read_chain_MCMC(fileName)

Both methods take a single string argument specifying the file name used for exporting or loading the chain results.

In most cases, these methods are not required. They become useful when a computation finishes without reaching convergence and the user wishes to extend the run. This can be done with the continueCalculation method, which executes additional iterations of the MCMC algorithm in order to try to achieve convergence. Its prototype is:

continueCalculation(new_Ns)

This method takes a single integer argument that specifies the number of additional iterations to run. In this case, it may be useful to reload one of the previously computed chains with read_chain_MCMC before calling continueCalculation. Regardless of which chain is loaded, the calculation will continue for all initialized chains.