Step by step example for first time users.


For users who have been familiar with the traditional FDM or FEM methods employed by other commercial packages  -you will find that the Boundary Element Method is quite different and so it requires different methods to defined electrodes and rays, so for you there will be a novel 'learning curve'.

We recommend that all new users should start by looking at the videos available on the website.

We also suggest looking at the Users Guide, which is based on the hard copy that used to be supplied, and which still covers the basic information.

Please remember that CPO Ltd are happy to offer new users free help with their first simulation.

For the present step by step we have chosen to describe how the data file test2d01.dat is run on CPO2D program (but the running of the CPO2DS, CPO3D and CPO3DS programs is very similar).


You have already clicked on the CPO2D icon to open the program and have clicked on Help at the right-hand end of the top bar, and Help on CPO, to reach the present page. 

Click on File on the top row and then click on Open for running and databuilding (or instead of clicking, look for the underlined letter, in this case F, and use the keyboard to type Alt+f , then o).

Make sure that the folder named at the top is the one that holds the 2D data files.

Select test2d01.dat.

Read the messages then click on OK (or press return).

Click on Run and see the program calculate the surface charges and trace the rays.

Click on OK.

The program has now finished and the resulting electrodes and rays can be seen on the graphics sheet.

The underlying information sheet contains the information that has been put into the ray output file.

Click on Zoom or Contours or View, and in each case experiment with all the options.

Now experiment with changing some of the parameters of the model:


The file test2d01 is read-only, so save it to another file using File/Save as

Now we can make changes to the electrodes, voltages and rays by using the databuilder.

Click on Databuilder and experiment with some of the options, such as the following:

Click on Filenames and comment line.

Type in a new name for the processed data file (and perhaps a new directory).

Similarly type in a new name for the output data file.

Click on Electrodes.  The first time you do this a notice will appear asking you to 'CHECK HERE' if you are not using user-supplied equations to define electrode shapes, which you are not, so check and exit and enter again.  Now you will see the data on the first electrode, the inner sphere. Then click on the Edit option on this screen, and then change the radius of the inner sphere (that is, change the two numbers 0.75 to a differen number, say 0.5).

Click on Run and you will see this change.

Click on Voltages, and the change the voltage applied to the inner sphere, say.

Click on Sources of rays… and you will see that Individual rays are already selected.

Click on Edit and you will see the data for the first of five individual rays.

Use Next to go to the last of the individual rays, then click on Add to add a sixth ray. The box will reproduce the data of the last ray, so change some of the parameters.

If you want to save these changes, use File/Save.

Finally Exit.

If you want to see a record of the results, look at the output data file that you named.

Data from the Information box can be copied onto the clipboard, but it is necessary to CLOSE A RUN before copying into notepad, etc, or else some of the last lines might not be copied.