Re: Odepkg

[Carlo De Falco]

> On 31 Jul 2017, at 20:26, Thomas D. Dean <address@hidden> wrote:
> 
> The odepkg I use was installed with an earlier version of octave, before the 
> pkg was moved to unmaintained.  It seems to work OK.

It is not a good idea to keep a version of a package that was installed
with an older version of Ocatve, changes in the Octave ABI can lead
to unpredictable behaviour.

Also, if you installed odepkg with Octave < 4.2 loading odepkg will shadow
the ode solvers that were moved into Octave core.

This may explain the behaviour you have experimented with ode45, try again
to run your example after unloading odepkg:

pkg unload odepkg
fvdb = @(vt,vy) [vy(2); (1 - vy(1)^2) * vy(2) - vy(1)];
vopt = odeset ("RelTol", 1e-3, "AbsTol", 1e-3, "NormControl", "on", 
"OutputFcn", @odeplot);
ode45 (fvdb, [0 20], [2 0], vopt);

c.