Re: DDE solvers / How to set HISTORY

[Maurizio De Pittà]

Thanks Stephen,

precisely the line of code I needed. Now it makes sense.

Cheers,

M

On Sat, Jan 19, 2019 at 11:35 PM Montgomery-Smith, Stephen <address@hidden> wrote:

On 1/19/19 1:57 PM, Maurizio De Pittà wrote:
> Dear all,
> I am troubled by the DDE solvers in octave. My question follows this
> question that sadly remained without answer:
>
> http://lists.gnu.org/archive/html/help-octave/2016-08/msg00064.html
>
> In particular, I cannot understand what is the "matrix" that I need to
> provide as HISTORY in the input argument of any of the
> octave/dde-solvers -- i.e. any of the odeXXd solvers in the odepkg.
> There is no explanation on the specifics of this matrix and why it seems
> to be required to be of size n_var * n_delay. This is very different
> from MATLAB implementations. Any insight would be helpful.
>
> Thanks in advance.
> Maurizio
>
>

Look at https://searchcode.com/codesearch/view/9530442/ in particular
this piece of code:

for vcnt = 1:length (vlags);
  vhmat(:,vcnt) = feval (vhist, (vslot(1)-vlags(vcnt)), vfunarguments{:});
end

It suggests to me that it is the matrix whose columns are values of y
calculated at the start point minus the values of the lags.