Using Open Source Softwarein Electrical Engineering Courses

Anthony RichardsonUniversity of Evansville

richardson@evansville.edu

Why Use Open Source?

Multiplatform - Windows, Linux, Macintosh. Users are free to choose their own operating system.

Reduced software costs for students and the university.

Access to source code helps to guarantee that file formats will not be made obsolete.

Encourages ethical behavior with regard to the copying and use of software.

Office Software

There are several open-source software packages available, but the most popular, cross-platform, open-source suite is probably StarOffice-OpenOffice.org. Word processing, Spreadsheet, Drawing, Image

Processing, and Presentation components. Full featured. High Quality. Very good MS Office import/export capability. Windows, Linux, Solaris (Mac port in progress)

OpenOffice Writer

OpenOffice Calc

Mathematical Plotting

Although a number of packages are available, Gnuplot is very well-known and has been ported to several platforms (Windows, Linux, Mac). 2D and 3D capability. Over 50 graphics output formats. Very fine-grained control over graph contents. Command-line or script file input. (Well suited as a

back-end for web based (CGI) graphics.)

Example Gnuplot Script

The last four lines will produce the basic graph. Note the complex number and function support.set nokey; set format x "%8.0f"; set mxtics 10; set grid; set grid mxticsset xlabel "Frequency (Hz)"set ylabel "Magnitude (dB)"set y2label "Phase (degrees)"set title "Frequency Response of Lowpass Filter"set label "Phase " at 10000,-22 rightset label "Magnitude" at 100000,-22 rightset logscale x; set xrange [1:1e6]set angles degrees; set y2ticsf0 = 10000; H(f) = 1./(1.+{0,1.}*f/f0)plot 20*log10(abs(H(x))), arg(H(x)) axes x1y2

Example Gnuplot Output

Gnuplot 3D Example

Web-Based Bode Plotter

Web-Based Bode Plotter

Numerical Analysis

Scilab, RLaB, and Octave are available and have similar capabilities. All are available for Windows and Linux.

Scilab appears to have the most extensive set of toolboxes and also includes the Scicos dynamic system simulator.

Example Scilab Session

Scilab Graphics

Scicos System Simulation

Computer Algebra

Maxima is available for both Windows and Linux. It does not have as many features as Mathematica,

Maple, or Derive, but is still very useful for the types of problems encountered in undergraduate EE courses.

Example Maxima Session

Maxima Graphics

Programming

The cygwin tools and libraries provide a UNIX environment for Windows.

Includes compilers/interpreters for C, C++, Fortran, Java, Perl, Tcl/Tk, and Python.

A large number of UNIX tools are included. Support for UNIX system calls as well as

Windows console and graphical applications.

Circuit Simulation

Although there are a couple of open-source circuit simulation programs, nothing seems to be available for both Windows and Linux (yet!).

The open-source Wine software can be used to run many Windows applications under UNIX (without a Windows OS). Wine is still in development, but the I have successfully run the MicroCap simulator (student version 6.0) under UNIX using Wine.

MicroCap Under Wine