Examples of how complex numbers and complex exponentials
can be handled by MATLAB.

PhasorRaces began as a speed drill for testing complex addition.
Now it includes many other related operations that can be tested
in a "drill" scenario: adding sinusoids, z-transforms, etc.
A timer starts as soon as the problem is posed, so that a
student can try to solve questions quickly and accurately.

ZDrill is a program that tests the users ability to calculate the result
of simple operations on complex numbers.
The program emphasizes the vectorial view of a complex number.
The following six operations are supported:

- Add
- Subtract
- Multiply
- Divide
- Inverse
- Conjugate