Post processing

Post processing

The Post processing tab is used for creating post-processing variables. It can handle several types of data:

• Parameters: standard real parameters of submodels, or global parameters.

• Simple variables: standard submodel variables.

• Compound variable for post processing

Compound output variables; These are defined by mathematical expressions involving parameters, simple variables and compound variables.

Figure 137: Post processing results

Post-processing variables

Post-processing variables

A post-processing variable is composed of the following elements:

• Name: the unique name of the variable in the system

• Title: a free field used to create a variable title

• Expression: this can contain numerical values, variables, parameters (including global parameters) or post-processing variables from any system.

• Default result set: the result file from which variables are read

• Value: the variable final value. If you have not enabled Update after simulation through the Tools > Advanced menu, this value is not updated until you click the update button. The value is only displayed when you click the update button (after a modification of parameters and a simulation run).

• Unit: the unit you wish to use for the post-processing variable. Note If you create a post-processing variable by dragging and dropping a variable, it will adopt the unit of the chosen variable. If you create a new post-processing variable by adding it directly in the Post processing tab, the unit will be null by default. The unit selected is only for display purposes. If you modify your expression, please make sure you adjust the unit accordingly.

Variable expressions

Variable expressions

Variables are referred to via their variable paths: variable_name@component_path

Variable path

You obtain the variable path from the Variable view. Select the component the variable belongs to (on the sketch), and then right-click the variable in the Variable view and select Copy variable path.

You can now paste the variable path into the expression field of the Post-processing tab.

Note

You can refer to a variable or parameter from another system. In this case, append system_name to the variable path. For example: x@Body:QuarterCar2.. Here, the system name QuarterCar2 is appended to the variable path.

You can also access the entire list of available variables and mathematical functions by opening the Expression Editor through the browse button .

Note

When you edit an expression in the Post processing tab, you can open the Expression Editor. For more information, please consult Expression editor.

When the Expression Editor is opened from the Post Processing tab, the Declared operands and constants tab gives access to all the variables used in the Simcenter Amesim Run model, including the ame_simulation_time ame_simulation_time variable, which provides the simulation time.

As well as simply dragging (one or more) parameters or variables onto the Post processing tab, you can apply them directly to existing parameters or variables and specify the operation you wish to perform in the same action.

Figure 138: Dragging to the Post processing tab

When you drag a parameter or variable onto an existing line in the Post processing tab, a contextual menu proposes the following options:

• Add +: perform an addition with the existing expression.

• Subtract -: perform a subtraction with the existing expression.

• Multiply *: perform a multiplication with the existing expression.

• Divide /: perform a division with the existing expression.

• Add To List: add the variable or parameter to the list in the post processing tab without appending it to an existing expression.

You can drag multiple parameters or variables to the Post processing tab in the same way.

Figure 139: Adding multiple variables

Plotting post-processing variables

You can drag and drop a post-processing variable to the sketch area to plot it, or select Plot from the contextual menu:

Saving and loading post-processing variables

If you have a large number of post-processing variables, for example to perform a large number of different study types, you may find it useful to be able to reduce the list to only those post-processing variables currently-required. You can also exchange such variables with other users. This is done through the save and load functions in the Post processing tab’s contextual menu:

When you select either of these options, a file browser opens allowing you to specify a location in which to save a post-processing variable, or from which to load a post-processing variable.

• Variable compatibility

It is the user’s responsibility to ensure that imported post processing variables are compatible with the target system. If an imported variable is incompatible, it is highlighted in red (when you press the refresh button: Figure 140: Incompatible post-processing variable

Figure 141: Update error message

• Overwriting variables

If the Name of the variable you are trying to import already exists, you will be prompted whether to overwrite it or leave the original variable unchanged:

Warning Only the Name of the post-processing variable is considered when using the load function. If you try to load a variable A1, and your list already contains a variable A1, it does not matter if the expressions of the two variables are different, you will either have to overwrite the existing variable (replacing its expression), or skip the loading of the new variable.

Organizing post-processing variables

If you have a large number of post-processing variables, you can organize them into groups. You create a group through a right-click in the Post processing tab:

Figure 142: Creating a post processing group

Once you have created a group, you can drag new or existing post processing variables into it:

Figure 143: Dragging a variable to a group

You can apply the usual operations to grouped post processing variables:

Figure 144: Working with post processing variables in a group

You can also drag post processing variables back out of a group if necessary.

Exporting post-processing variables

Exporting post-processing variables

post-processing variables exporting

You can export post-processing variables to a .csv file by right-clicking in the Post processing pane and selecting Export variables to CSV file or Export all variables to CSV file.

A file browser opens allowing you to specify a destination filename (or folder, in case of batch runs) for the export. The default path is to the same directory as where the model is stored. You can modify this as required.

Figure 145: Exporting post-processing variables

The resulting .csv file contains the following information:

• Date and time of the export

• System name

• Result set

• Name of the exported variable(s)

• Title of the exported variable(s)

• Units of the exported variable(s)

• Exported variable(s) values

Export variables to CSV file: export the currently-selected post-processing variable. The exported .csv file will contain the data corresponding to the selected post-processing variable.

Figure 146: Exporting a single post-processing variable

Export all variables to CSV file: export all the post-processing variables to a .csv file. The exported .csv file will contain the data corresponding to all the post-processing variables present in the Post processing pane.

Figure 147: Exporting all post-processing variables

If you have performed a batch run, the results for each run in the batch will be exported to a separate .csv file in a sub-folder.

Figure 148: Exporting all post-processing variables from a batch run