Re: substitute for ode23s

[Sebastian Schöps]

Am 01.06.10 17:46, schrieb harsh_uict:
> I had a similar problem while trying to integrate an ode with ode2r instead
> of ode15s of matlab.  With
>        tspan = [T0 T1 ... TEND]
> octave gave an error
>        error: invalid conversion from real matrix to real scalar
> followed by a bunch of errors
>        error: octave_base_value::array_value(): wrong type argument `<unknown
> type>'
>
> But when i changed  tspan to
>       tspan = [T0 TEND]
> the errors disappeared.
>
> May have some thing to do with the way ode2r is defined, though I am not
> sure. Hope this works for you too.
>
> Harsh

Do you want fixed step sizes for your time integration or are you asking 
how to get the values at times T0, T1, ... TEND?

If you want a time integration with a single fixed time step 
(h=T1-T0=T2-T1=...), then

h=T1=T0
tspan = [T0 TEND]
odeset('MaxStep',h)
[...] = ode2r(...)

will do the trick.

In the second case you might need to adjust RelTol and AbsTol and then 
do an interpolation to get your data.

Bye
Sebastian