About Evaluation Groups
An evaluation group is analogous to a plot group: It has zero or more numerical evaluation nodes (all evaluation nodes that are also available under Derived Values) as subnodes. The Evaluation Group node contains common settings and also acts as the table to which its subnodes evaluate. The values in an evaluation group’s table can be reevaluated automatically when solving (see Update of Results). For information about the available evaluation nodes, see Derived Value Types. For information about the evaluation group tables, see The Table Window and Tables Node. To add an Evaluation Group node (), right-click the main Results node and select Evaluation Group. Then right-click the Evaluation Group node to add the evaluation nodes to be evaluated within that evaluation group. You can evaluate all nodes under an Evaluation Group node by right-clicking them or by clicking the Evaluate button ().
From the Evaluation Group contextual ribbon toolbar, you can also add evaluation nodes and evaluate them. In addition, you can create graph plots and surface plots by clicking the Graph Plot () and Surface Plot buttons, respectively; click the Clear button () to clear the selected evaluation group; and click the Copy to Table button () to copy the selected evaluation group to a table.
The Evaluation Group node’s Settings window contains the following sections:
Data
In this section you define the data to use for the evaluations. See Common Results Node Settings for more information.
Storage
You can also store the evaluation group’s table data on the file system instead of, or in addition to, storing it in the model. Select a way to store the table data from the Store table list:
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Select In model (the default) to store the table data in the model.
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Select On file to store the table data in the model to a file that you select by first clicking Browse or enter into the Filename field.
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Select In model and on file to store the table data both in the model and on the file system.
For the storage in the model, specify the buffer size in the Maximum number of rows field. The default for new evaluation group tables is taken from the Results page in the Preferences dialog box (factory setting: 10,000 rows). If the table size exceeds that number of rows, the software removes rows from the top. If you use a large number, most table data will fit in the table without being truncated.
The row limit applies to table data in the model only and not to tables with data stored in a file.
If you change the storage format to or from storage on file, then click Update () in the Storage section’s header to refresh the contents of the table.
Transformation
You can make a transformation of the evaluations in the evaluation group.
Select the Transpose check box to transpose the data in the Evaluation Group window so that the table presentation contains row headers instead of column headers.
From the Type list, choose one of the following transformation types:
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 None, for no transformation.
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 Sum, for the sum of all evaluations.
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 Average, for the average of all evaluations.
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 Difference, for the difference of all evaluations (evaluation1−evaluation2−evaluation3, and so on)
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 General, for a general expression, which can include global parameters and mathematical and physical constants, for example. Enter the expression for the general transformation in the Expression field. To refer to the evaluated results in the subnodes listed in the table below (in the Feature column), use the corresponding tags listed in the table’s Tag column. For example pi*pev1/pev2 for pi times a quotient of the values from the Point Evaluation 1and Point Evaluation 2 subnodes. The expression is evaluated elementwise.
Format
In this section, use the Include parameters list to control which parameters value columns to include in the evaluation group’s table: Use Automatic (the default) to include the parameter value columns are included for the first active evaluation subnode, which is a good choice if all evaluation subnodes have the same parameter value columns. Otherwise, use On to include all parameter value columns, or use Off to include no parameter value columns.