In most cases, when you add an output to a Distribution Result (via the Add Result… button in the Result Properties dialog), you will simply be adding a standard output (such as the output of an Expression element or the the primary output of a Reservoir element). However, several types of elements in GoldSim produce a specialized output referred to as a Distribution output, and this output type can also be added (and viewed) in a Distribution Result.
Distribution outputs are complex outputs that represent all the statistical information necessary to define a probability distribution. They can only be produced by Stochastic elements, SubModels and Spreadsheet elements.
These outputs can be clearly identified when viewing the output port of an element:
Note the the Distribution output has a different appearance than the other three standard outputs (it is gray rather than blue)
In some situations, you may want to add such an output to a Distribution Result. There are two primary cases where this can be of value:
1. You wish to carry out a nested Monte Carlo simulation (using a SubModel). In order to view the results, you would add a Distribution output from a Monte Carlo SubModel to a Distribution Result element in the parent model.
2. You may want to compare a sampled distribution to a specified analytical distribution (e.g., to see how closely the sampled distribution matches a particular distribution such as a Normal or Weibull).
This is possible because Stochastic elements always have a Distribution output and if you view the Distribution output for a Stochastic in a Distribution Result it will display the analytical distribution (as opposed to the sampled distribution for that Stochastic). In the example below, a Stochastic element is defined (as a Normal) and the model is run for 300 realizations. Two of its outputs are added to a Distribution Result: the primary output and the Distribution output:
The Result display would look like this:
The primary output (Stochastic1) shows the sampled distribution. The Distribution output (Stochastic1.Distribution) shows the analytical distribution shape.
Learn more about:
Importing Stochastic Definitions Using a Spreadsheet Element