On 10/17/2015 04:41 AM, Carlo De Falco wrote:

> On 16 Oct 2015, at 20:26, Rik <

[hidden email]> wrote:

>

>> The non-Matlab compliant options have been removed. See this changeset (

http://hg.savannah.gnu.org/hgweb/octave/rev/00caf63edcdf).

> I think your changeset makes the functions integrate_constant and integrate_n_steps

> useless as there is now probably no way to trigger their use through the options.

Not useless. Unrecognized options can still be set, and Octave will only

print a warning, but otherwise pass the option through. In ode45.m the

decision on which algorithm to use is based on the options TimeStepNumber

and TimeStepSize. Even before removal, odeset() would have returned empty

entries by default for these fields resulting in the adaptive algorithm

being chosen. Just as before, one will have to specifically set these

options with opts = odeset ("TimeStepNumber", XXX, "TimeStepSize", YYY) in

order to get a different solver. The only change will be the warning,

"odeset: unknown field 'TimeStepNumber' in ODE options".

>

> Do we want to support that behaviour, even though it is not present in Matlab?

> Maybe Sebastian's proposal to have an (non compatible) option to pass a list

> of fixed time steps to use for integration is easier to support and more useful?

I can't answer these questions as my perspective is only about how to bring

the ODE code into the core. Generally, however, we like to think of Octave

as a superset of Matlab; It should be able to do everything Matlab does,

but it certainly is okay to do more.

--Rik