## Online Exercises

### Primal-Dual One-Phase Simplex Method

Below is a java applet that will present a set of linear programming
problems for you to solve.
It is similar in design to the
*advanced pivot tool*.
You're job is to solve each problem (either by
finding an optimal solution or demonstrating that the problem is infeasible or
unbounded). After correctly solving a problem, the applet will immediately
give you a new one. After you have solved all the problems in the set,
press the *Submit* button to email your score to your instructor
(whose email address must be supplied below).
Each problem must be solved using the *Primal-Dual One-Phase simplex
method*.
Any attempt to make an incorrect pivot will be rejected but your score
will be increased by one. As always, low scores are better than high scores.
When a tie exists for choosing an entering or leaving variable,
you may use any tie-breaking rule you
like.

The set of linear programming problems to be solved
is determined by specifying the number
of rows, the number of columns, the seed,
and the number of problems in the set.
Your instructor will tell you what values to use for these
fields. Make sure that you enter exactly what your instructor tells you for
otherwise you will be doing the wrong set of problems and it will be impossible
to fairly evaluate your performance.

Also, be sure to enter your email address and your instructor's email address.

When you are ready to begin, press the *Go Pivoting* button
and then, when the pivot window pops up, press the *Start* button.

Don't forget that incorrectly pressing one of
the termination buttons (*Optimal*, *Unbounded*, or
*Infeasible*) counts as an extra pivot, so press these buttons only when
you are confident that it is the correct thing to do.

Final note: if for any reason you wish to start over, you may press the
*Exit* button to quit the exam. At that point you can start afresh.
Of course, at some time before this online assignment is due you must
go to the end and submit a score.

For more information on how to use this applet, go the the
*advanced pivot tool*
and read the text there.

**
Bugs.
**
This applet works fine when accessed via Netscape3 on most UNIX workstations
and it works fine with either Netscape4 or InternetExplorer4 on WindowsNT. Most other
browser/platform combinations do not work correctly. The problem seems
to be due to bugs in the browser's JAVA interpreter
as implemented on the given platform.
If you have trouble getting the applet to behave as described above, try
finding a different browser/platform combination.