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MCSim User' Manual

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6.3.7 SetPoints() specification

To impose a series of set points (i.e., already tabulated values for the parameters), the global section can include a SetPoints() specification. It allows you to perform additional simulations with previously Monte Carlo sampled parameter values, eventually filtered. You can also generate parameters values in a systematic fashion, over a grid for example, with another program, and use them as input to MCSim. Importance sampling, latin hypercube sampling, grid sampling, can be accommodated in this way.

This command specifies an output filename, the name of a text file containing the chosen parameter values, the number of simulations to perform and a list of model parameters to vary. It has the following syntax:

 
SetPoints("<OutputFilename>", "", <nRuns>, 
          <identifier>, <identifier>, ...);

If a null string is given for the output filename, the set points output will be written to the same default output file used for Monte Carlo analyses, `simmc.out'.

The set points file name is required and must refer to an existing file containing the parameter values to use. The first line of the set points file is skipped and can contain column headers, for example. Each of the other lines should contain an integer (e.g., the line number) followed by values of the various parameters in the order indicated in the SetPoints() specification. If extra fields are at the end of each line they are skipped. The first integer field is needed but not used (this allows you to directly use Monte Carlo output files for additional SetPoints simulations).

The variable nRuns should be less or equal to the number of lines (minus one) in the set points file. If a zero is given, all lines of the file are read. The format of the output file of set points simulations is discussed below (see section 6.6 Analyzing results).

Following the SetPoints() specification, Distrib() statements can be given for parameters not already in the list (see section 6.3.5 Distrib() specification). These parameters will be sampled accordingly before to performing each simulation. The shape parameters of the distribution specifications can reference other parameters, including those of the list.


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