ODE Software for MATLAB

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.

For use with version 7.7 of MATLAB.

This is only a maintenance update to make the software run well under version 7.7 of MATLAB.

Two files are needed:

For use with version 7 of MATLAB.

This is only a maintenance update to make the software run well under version 7 of MATLAB.

Two files are needed:

For use with version 6.5 of MATLAB.

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:

For use with version 6.0 of MATLAB.

This is only a maintenance update to make the software run well under the new version of MATLAB.

Three files are needed:

For use with version 5.3 of MATLAB.

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.

Three files are needed:

For use with version 5.2 of MATLAB.

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:

For use with version 5 of MATLAB.

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:

For use with version 4.2 of MATLAB.

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:

For use with version 4.0 of MATLAB.

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:

For use with version 3.5 of MATLAB.

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:

Other MATLAB ODE Solvers.

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.

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.

MATLAB code for a square wave.

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