Running a calculation

Running calculations is an important aspect of Train Noise Expert; here is an introduction to the procedure, and some background information about what happens behind-the-scenes.

Before running a calculation, it’s a good idea to spend some time making sure that your model has been put together well, with all input files present and correct input parameters. Calculations can take some time to process, so time spent checking early on can save time later re-running calculations.

To run a calculation, simply go to ‘Project’ in the menu bar and select one of the calculation options. The options available to you depend on your licence; unavailable options will be greyed-out.

Menu options for running calculations.

For rolling and external noise calculations, a dialog box will appear. This allows you to add a short description for this calculation. It can be left blank if you wish. You can also abort the calculation at this point.

Input for a calculation description.

The progress of the calculation is shown in the run log. If you wish to abort the calculation at any point, you can click the ‘abort’ button at the bottom-right of the screen:

Button for aborting calculations.

When the calculation is complete, a dialog will pop up to tell you, and in most cases the results will automatically be plotted and shown. These results are all saved in the project folder and can be view again later, see viewing results.


What happens when a calculation runs? Well, this depends slightly on the type of calculation, but in general this is what happens:

  1. The user is asked for a description of the calculation.
  2. A new folder is created in the ‘results’ directory of your project, with the date and time of the calculation.
  3. Train Noise Expert goes through your model data and creates an appropriate folder structure in the new results folder.
  4. Input text files are generated and placed in the correct locations in the folder structure.
  5. For each situation (for external noise calculations), or wheelset (for rolling noise calculations), Train Noise Expert will launch a MATLAB executable, telling it where to find the files to process. The MATLAB runtime processes these files and runs the calculation, reporting its progress back to Train Noise Expert as it does so.
  6. Once all situations and/or wheelsets have been calculated, a confirmation popup is displayed, and the plotted results are shown.


Some errors can be detected at an initial stage. For example, when Train Noise Expert generates the input files for the MATLAB executable, it checks that the file paths to any of your data files are correct, and will tell you if any files are missing.

If errors are encountered by the MATLAB executable, then the calculation will stop and an error message will be shown. MATLAB errors are usually due to a problem with an input file. By checking the run log and the text of the error message, you may be able to track down the problem. To try and isolate problems, it might be a good idea to disable other situations or components while you investigate.

For assistance with persistent errors, please contact us.