Problem Set 2,  6.964  Pervasive Computing, September 25, 2001

Due: Oct 11, 2001

Title:  Equation Specifier via widgets on the ipaq



The purpose of this assignment is to learn how to build an application
that uses buttons, menus, lists, and pop-up windows for user input on
an iPaq.  There are many ways to build such applications; we are going
to suggest using the GTK+ package.  GTK+ is a set of runtime routines
that manage the layout of widgets on the screen and associates a set
of events and call-backs with actions associated with the widget.

Glade, a GUI program that automatically generates the
GTK+ calls is a great way to start.  You can then muck around with the
low-level GTK+ routines, either in C, C++, or Python. Python is simplier but
may be hard to figure out what to do; C requires either a native
compilation on the ra.lcs.mit.edu maching or a
cross compilation step.   Glade information can be found at
http://glade.gnome.org. 

The assignment is to build the buttons to input mathematical
equations.  I have specified a minimal grammar; feel free to extend
and generalize.  Commands such as simplify or integrate will
eventually be hooked up to a mathematica or maple backend.  For now,
just have those buttons do something silly until we learn about
network communication.  You can also postpone the actual display of
the equation until we get some flash cards for the ipaq. 

You have two weeks for the assignment and may work in pairs.  The goal
of this project is to make sure you know how to build a simple input
module for the iPaq as it will be needed for the final project.  This
current assignment is just a way to get you started.


Commands:

* Define equation e<number>
* Simplify e<number>
* Display  e<number>
* Differentiate  e<number> 
* Differentiate  e<number> with respect to <variable>
* Integrate  e<number> 
* Integrate  e<number> with respect to <variable>


Equations:

*  <variable> plus <variable>     e.g. x+y
*  <variable> minus <variable>    e.g. y-e2
*  <function> of <variable>       e.g. g(x)

*  <variable> times <variable>           e.g. x*y
*  <variable> multiplied by <variable>   e.g. x*y
*  <variable> divided by <variable>      e.g. x/y

*  <variable> to the power of <variable>   e.g. x^y
*  <variable> to <variable>                e.g. x^y



Where <variable> can be either "u, v, w, x, y, z"  or e<number>
and   <function> is either "f, g, h"