Simulation Fitting Node

The Simulation Fitting node fits a set of candidate statistical distributions to each field in the data. The fit of each distribution to a field is assessed using a goodness of fit criterion. When a Simulation Fitting node is executed, a Simulation Generate node is built (or an existing node is updated). Each field is assigned its best fitting distribution. The Simulation Generate node can then be used to generate simulated data for each field.

Although the Simulation Fitting node is a terminal node, it does not add a model to the generated models palette, add an output or chart to the outputs tab, or export data.

Note: If the historical data is sparse (that is, there are lots of missing values), it may difficult for the fitting component to find enough valid values to fit distributions to the data. In cases where the data is sparse, before fitting you should either remove the sparse fields if they are not required, or impute the missing values. Using the options on the Quality tab of the Data Audit node you can view the number of complete records, identify which fields are sparse, and select an imputation method. If there are an insufficient number of records for distribution fitting, you can use a Balance node to increase the number of records.

Using a Simulation Fitting node to automatically create a Simulation Generate node

The first time the Simulation Fitting node is executed, a Simulation Generate node is created with an update link to the Simulation Fitting node. If the Simulation Fitting node is executed again, a new Simulation Generate node will be created only if the update link has been removed. A Simulation Fitting node can also be used to update a connected Simulation Generate node. The result depends on whether the same fields are present in both nodes, and if the fields are unlocked in the Simulation Generate node. See the topic Simulation Generate Node for more information.

A Simulation Fitting node can only have an update link to a Simulation Generate node. To define an update link to a Simulation Generate node, follow these steps:

  1. Right-click the Simulation Fitting node.
  2. From the menu, select Define Update Link.
  3. Click the Simulation Generate node to which you want to define an update link.

To remove an update link between a Simulation Fitting node and a Simulation Generate node, right-click on the update link, and select Remove Link.