Working with multiple data sets

The Post-processing feature can process variables using results from different result sources. For example, you can process variables from an experiment in conjunction with results from a batch run. Moreover, you can access an experiment's results without needing to load and apply the experiment.

Default Result Set

The Post processing tab contains a Default Result Set column, which displays all the available result sets:

In this example we can see that as well as the standard run (ref) and 5 batch runs, we also have access to the results of some experiments (exp_1.1, exp_1.2...).

You can select the result sets individually for each variable using this Default Result Set column, but also globally using the Result Set drop-down list.

If variables are configured to a different result set, the global Result Set drop-down displays ???.

Post-processing allows us to specify each of these different results in our expressions, meaning we can specify different result files (current, batch or experiment) in one user variable.

Overview

The result set selected in the Default Result Set column is applied to the variables of post-processing expressions that do not have a result set explicitly determined in square brackets [ ].

For example:

Title	Expression	Result set
A1	var@comp	set 1
A2	A1	set 2
A3	var@comp[2]-var@comp	set 1

Note that we have specified [2] in the expression of A3.

• A1 contains the values of var@comp taken from the result set named "set 1"

• A2 contains the values of var@comp taken from the result set named "set 2"

• A3 is equivalent to a difference between the values of var@comp from "set 2" and from "set 1".

If, in an expression, all the variables used in an expression have their result sets explicitly defined, the Default Result Set column serves no further purpose, and is disabled:

In the above example, the A3 variable expression is as follows: (x1@mass_friction_endstops[1])-((x1@mass_friction_endstops_1[2]))

This means that both variables in the expression are set to use specific result sets: [1] and [2]. Therefore the Default Result Set column is disabled. Moreover, when a result set is defined (using square brackets), the result set to use for this variable is fixed for every post-processing variable which uses it in its expression.

Syntax

Variables and result sets are defined using the following syntax:

• <var_name@component_name>[N] In the above example, [N] is used to specify the number of a batch result file.

• <var_name@component_name>[exp_1_batch_run.N] In the above example, [N] is used to specify the number of a batch run in an experiment named exp_1.

Examples

In the example above, the variable x1@mass_friction_endstops- reference result set, is subtracted from the variable x1@mass_friction_endstops_1- batch run 2 result set.

• A1 = x1@mass_friction_endstops_1 - result set 2

• A2 = A1 (x1@mass_friction_endstops_1 - result set 2)

• A3 = A1[1] In this case the variable specifies both result set [2] in A1 and result set [1] in A3. In effect the expression is saying x1@mass_friction_endstops_1[2][1]. In this case, the result set used will be [2]. Only the first definition is kept.

• A1 = v1@PS_CarBody - reference result set

• A2 = v1@PS_CarBody[1]

• A3 = A1-A2[2] In this case the variable is saying v1@PS_CarBody[2]-va@PS_CarBody[1][2]. In this case, the result set used will be [1]. In other words, this gives: v1@PS_Carbody[2]-v1@PS_Carbody[1].

Remember that the expression will display a tooltip to show the result of the expression.

Errors

If a post-processing variable A has a result set defined (using square brackets), and if in the expression of another post-processing variable B square brackets are used to specify A, the expression will be invalid. Invalid square brackets are highlighted to show that they are invalid:

Here we see that A2 will use result set 3. A3, however, wants A2 to use result set [1]. The expression is therefore invalid, and the error is displayed.

Result sets in Watches

When your simulation contains multiple result sets, you can select those result sets individually for each variable in the Post processing pane, but also globally in the Result Set drop-down list.

Figure 151: Watch variables pane Result Set drop-down list

In figure Figure 125, we see three Watch variables each configured to a different Result set (3, ref, and 5). Consequently, the global Result Set drop-down displays ???. We can easily set all three Watch variables to the same result set by selecting one of the available result sets from the global Result Set drop-down list:

Figure 152: Setting all Watch variable result sets

In figure Figure 126 above we are using the global Result Set drop-down list to switch all individual result sets to Result Set 6.