This is a nice interactive tool to study first order ODEs, which was originally created by John Polking at Rice University (together with other tools such as pplane and odesolve).
The original versions (see also here https://math.rice.edu/~polking/odesoft/solver.html for more information) only work up to MATLAB versions R2014a.
A great version of pplane8 which works in any MATLAB version can be found here: https://www.mathworks.com/matlabcentral/fileexchange/61636-pplane
Note that at the time of writing there are a couple of versions on file exchange (both called dfield9) from Gerardo Garcia (https://www.mathworks.com/matlabcentral/fileexchange/64437) and Iourii Kouznetsov (https://www.mathworks.com/matlabcentral/fileexchange/65886), however the former gives warnings for versions 2015a and later, and errors out for versions 2017b and later. The latter works without errors or warnings, but the text is disproportionally larger and out of place. Both versions have the toolbar on in the setup window and tend to place the display window a little out of reach in the upper right part of the screen sometimes.
This version of dfield8 is the closest to the original in look and feel, but it is faster, and it works for any version from R2014b on.
Giampiero Campa (2020). dfield8 (https://www.mathworks.com/matlabcentral/fileexchange/71408-dfield8), MATLAB Central File Exchange. Retrieved .
Gabriele, you can find pplane in the second link, here: https://www.mathworks.com/matlabcentral/fileexchange/61636-pplane
It works fine. If you need it go faster just comment out the "drawnow" instructions in the file.
Thanks a lot!
If your time allows, it would be great to have this porting also for pplane, as it used to be a very valuable tool for exploring systems' dynamics!
updated broken link in the description
Commented out the drawnow instructions to plot much faster. If you for some reasons want it to plot slower to follow the evolution in time, search for the drawnow instructions and remove the comment.