Creating a simple trace analysis

Having selected the signal “CarSpeed” for analysis, we now need to determine how to analyze it. This tutorial will utilize a calculation step to that end. Calculation steps can be created easily and are well suited for problems, which can be formulated in a single Python expression. These expressions can utilize a large number of predifined functions for typical analysis task (e.g. Edge, HoseAbsolute, see the Functions for use in expressions), which makes calculation steps a viable tool for solving even more complex problems.

To create a new calculation step within the trace analysis editor click on the symbol Calc_Symbol (“New Calculation”) under Episodes and trace steps.

../../_images/Tutorial_CreateNewCalculationstep.png

Creating a new calculation step

In the calculation step settings dialog move the cursor into the Expression line and press the “Down Arrow Key”. From the dropdown list choose the signal “Signal0” with a double-click. Add the threshold value comparison “<= 75” to the expression. The remaining settings can stay untouched for this tutorial.

The completed dialog should look like the following:

../../_images/Tutorial_NewCalculationstepSettings.png

Parameterization of a calculation step

Confirm and close the dialog of the calculation step via the button OK. Now add a plot to visualize the signal and the results of the calculation. Click on the button Plot_Symbol (New Plot) under Episodes and trace steps at the left edge of the trace analysis editor and accept the suggested options by clicking on OK.

The finished analysis should look like this:

../../_images/Tutorial_SimpleAnalysis_ReadyForAnalysis.png

The finished trace analysis

Having executed the trace analysis (see Preceding section) the result is displayed in the tab Test report. Navigate to the calculation step in the report tree. When this step is selected, details about its execution are displayed in the right subwindow:

../../_images/Tutorial_SimpleAnalysis_Testreport.png

Displaying the test result

The report contains the following central analysis results:

  1. The threshold of 75 km/h was violated. The trace analysis therefore delivers the result FAILED.

  2. The threshold violation took place between measuring time 44.400800 and 44.450200.

Info

Instead of defining the threshold value explicitly in the calculation step, you can also use the name of a package variable.

Additional elements and possibilities for trace analyses

In addition to calculation trace steps, there are other elements that can be used to design an analysis. Additional information can be found in the section Drafting trace analyses.