Variation Analysis

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Variation Analysis

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Using the Tolerance Analysis option of the Multiple Run Wizard, you can analyze the effects of variation of parameters / initial values on the performance of your model. Three methods of Tolerance analysis are supported in the Multiple Run Wizard. One of these methods is Variation Analysis.


Using Variation analysis, you can perform a predefined number of simulation runs with variation of parameter values according to a predefined distribution function. During the runs a given result is monitored. After the runs the statistical range of the result is presented. You can restrict the parameter distributions to get the result between desired bounds.

Parameters / Initial Values

1.From the Tools menu select the Time Domain Toolbox and then Variation Analysis.

A window opens asking you which parameters / initial values should be varied for the Variation analysis:


2.Add the parameters / initial values of your choice:
3.Click the Next button.


A window opens asking you which result should be monitored during the Variation Analysis:


4.Enter the result here using the various options of the window.
5.Click the Next button.

Run options

A window opens asking some simulation run options:


6.Select the desired run options and click the Next button.

A window opens with a summary of the chosen options. If your are not satisfied you can use the Back button to go to a previous window and change settings.

7.Click the Finish button to close the Multiple Run Wizard.
8.From the Simulation menu click the Multiple Run command to perform the Variation Analysis.

Variation Analysis Results

After simulation has been done, a Variation Analysis Results window will open, showing the results. A histogram shows the distribution of the result. Using the slider bar you can see how restraining the distribution of the parameters effects the distribution of the result.


You can select the following items:

Slider Bar: Select a parameter and restrict its distribution with the slider bar. You will see the histogram showing the result change.
Multiple Run Values: Choose this button to open the list that shows the output of the various runs performed during the Variation Analysis.
OK: Close the Multiple Run Results Window.


You can always re-open the Multiple Run Results window, by selecting the Multiple Run Results command of the View Menu.

9.By choosing the Multiple Run Values button, a new window is opened, showing output of the various runs performed during the Variation analysis:


You can select the following items:

Set Values: Choose the values of the selected run, as new parameter values of your model.
Create Datafile: Use this button to store the values of the selected variables on file. Use the control-key and shift-key to make multiple selections.