COMSOL 6.2 - 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 ) as subnodes. The 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 node (

), right-click the main node and select . Then right-click the node to add the evaluation nodes to be evaluated within that evaluation group. You can evaluate all nodes under an node by right-clicking them or by clicking the button (

Also, for evaluation nodes under an node where the selected dataset has the same nontrivial parameter structure as the dataset used in the parent evaluation group (typically, a solution that contains solution data for more than one time, eigenmode, or parameter), you can choose from where to take the solution parameters. From the list in the evaluation node, choose to choose a time, eigenmode, or parameter using the settings described below, or choose to use those values from the corresponding settings in the parent evaluation group. Using the settings from the evaluation group can make it easier to work with evaluation groups where multiple datasets are used.

From the 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 (

) and

buttons, respectively; click the button (

) to clear the selected evaluation group; and click the button (

) to copy the selected evaluation group to a table.

The node’s window contains the following sections:

In this section you define the data to use for the evaluations. See Common Results Node Settings for more information.

If you have defined a compatible configuration (see Configurations), which is typically a Multiselect Solution, the you can choose from the list (the default is ). With , choose a compatible configuration from the list to use its settings for the solution parameters such as time, eigenvalue, or parameter values to use.

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 list:

•

Select to store the table data in the model to a file that you select by first clicking or enter into the field. Click the downward arrow for the menu (

) to choose (

) and (if you have copied a file location) (

For the storage in the model, specify the buffer size in the field. The default for new evaluation group tables is taken from the field on the page in the 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 (

) in the section’s header to refresh the contents of the table.

You can make a transformation of the evaluations in the evaluation group.

Select the check box to transpose the data in the window so that the table presentation contains row headers instead of column headers.

From the list, choose one of the following transformation types:

•

, 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 field. To refer to the evaluated results in the subnodes listed in the table below (in the column), use the corresponding tags listed in the table’s column. For example pi*pev1/pev2 for pi times a quotient (ratio) of the values from the and subnodes. The expression is evaluated elementwise.

When the list is not , select the check box to include the evaluation of the child nodes in the evaluation of the transformation of those values.

Use the list to control which parameters value columns to include in the evaluation group’s table: Use (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 to include all parameter value columns, or use to include no parameter value columns.