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ODE Software for MATLAB
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DFIELD and PPLANE
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.
In addition there are
java versions of dfield and pplane available for
use on the internet.
ODESOLVE
odesolve is a MATLAB program for solving arbitrary systems of
ordinary differential equations. It is still in an early stage of
development, but it is fairly stable. Its use is described in the
third edition of Ordinary Differential Equations using
MATLAB. Further development of this product is awaiting feature
requests from users. Suggestions for changes in the design and for
additional features, as well as notification of bugs should be
directed to John
C. Polking.
Downloading the software
To download what you need, simply click on the appropriate links
below.
The files must be saved in a directory that MATLAB can find. If your copy of MATLAB cannot find dfield or
pplane, it is most likely because the directory in which you
saved the files is not on the MATLAB path. On modern versions of
MATLAB there is a path browser, which can be opened from the menu or
from the toolbar. This tool will enable you to add a directory to the
path.
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 once or twice each year.
This is only a maintenance update to make the software run well under
version 7.7 of MATLAB.
Two files are needed:
This is only a maintenance update to make the software run well under
version 7 of MATLAB.
Two files are needed:
The software has been rewritten using new features of MATLAB. The new
versions are described in the third edition of Ordinary Differential
Equations using MATLAB.
The file ppn6out.m is no longer required, so only two files
are needed:
This is only a maintenance update to make the software run well under
the new version of MATLAB.
Three files are needed:
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.
Three files are needed:
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. Three
files are needed:
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:
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.
Four files are needed:
These are the versions described in Ordinary Differential Equations
using MATLAB. They will work on any variant of version 4 of MATLAB.
Four files are needed:
If anyone has still not upgraded from version 3.5 of MATLAB, these files
will work. dfield was called df35 and
pplane
was called phpl35 in those days.
Five files are needed:
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.
-
Euler's method: eul.m
-
Second order Runge-Kutta: rk2.m
-
Fourth order Runge-Kutta: rk4.m
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: Tues April 23, 2002