The programs DFIELD and PPLANE are described in some
detail in the manual Ordinary
Differential Equations using MATLAB. There are several versions
of the software available for use with various editions of MATLAB.
DFIELD and PPLANE are copyrighted in the name of John
C. Polking, Department of Mathematics, Rice University. They are not in
the public domain. However, they are being made available free for use
in educational institutions. This offer does not extend to any application
that is made for profit. Users who have such applications in mind should
contact John
C. Polking.
Several versions of DFIELD and PPLANE are
available. In addition there are a couple of pieces of related
software.
We are beginning the process of reprogramming DFIELD and
PPLANE
in Java. Beta Java Applet versions are available for testing. Click on
the button below to run either the DFIELD or PPLANE Applet.
Click Button on Right for DFIELD
Click Button on Right for PPLANE
If you do not see the buttons above, it means that your browser
is not Java 1.1.6 enabled. This may be because:
1) you are running a browser that does not support Java 1.1.6,
2) there is a firewall around your Internet access, or
3) you have Java deactivated in the preferences of your browser.
Both Netscape
Communicator 6.2 and Microsoft
Internet Explorer 5.0 include Java 1.1.6.
Delivery of the software via the world wide web is probably the easiest
method for users to employ. The disadvantage is that no record is kept
of the downloads. It would be greatly appreciated if you would contact
John
C. Polking, and tell him how you are using DFIELD and
PPLANE,
what level of course you are teaching, how many students you have, and
what you think of the programs. If you acknowledge your use of the programs
in this way you will be informed as new versions are released. Since changes
are made as bugs are discovered and corrected and as good, new ideas are
implemented, this will occur a few times each year.
To download what you need, simply shift-click on the appropriate links
below.
This is only a maintenance update to make the software run well under
the new version of MATLAB. I hope to make a more substantial upgrade
later in 2001.
The most significant change from the older software is a better way of
handling temporary files. For most people this will not be important,
however the change is essential to making the software run on the
Linux operating system.
Previous changes
There are two major changes.
I have added an option that allows the plotting of level curves
on the Display Window. Its use should be self explanatory.
I have integrated the DFIELD and PPLANE menus
with the new MATLAB menus that allow plot editing of graphical
figures. In addition, I have integrated the Toolbar into all
graphical figures. The integration
works pretty well, but there are some glitches. This must be
considered a work in progress, both for The MathWorks and myself.
The user should approach plot editing with some care. I would very
much like to hear what the users think about this
new feature.
This is a minor revision of DFIELD and
PPLANE. There is one major difference. Now what were
Parameter edit boxes will accept mathematical expressions as well. A
description is available.
DFIELD and PPLANE have been completely reworked to take
advantages of the much improved programming capabilities of version 5 of
MATLAB. There are a number of new features. A description
is available.
Three files are needed:
dfield5.m (New
version posted on September 4, 1997)
These are essentially the versions described in Ordinary Differential
Equations using MATLAB. There have been some features
added and bugs removed. Version 4.2 of MATLAB is required.
It is a very easy task to program in MATLAB the elementary single step
solvers which are typically discussed in beginning ODE courses. However,
if you do not want to take the time, here they are. These routines should
work in any version of MATLAB. They have been revised so that the syntax
of the solvers is closer to the ODE suite in version 5 of MATLAB.
MULTIGRAF
is an easy to use MATLAB routine which enables the placing
of up to six MATLAB figures on one page. Special attention is payed
to DFIELD and PPLANE figures.
Another simple code, this time to produce a square wave. MATLAB has a version
of this, but unfortunately only in an add on toolbox. For those who might
want to use it, here
it is.John C. Polking
<polking@rice.edu>
Last modified: Sun Aug 29 19:23:55
Central Daylight Time 1999
