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Re: lsode use
From: |
Juan Pablo Carbajal |
Subject: |
Re: lsode use |
Date: |
Wed, 26 Aug 2015 10:27:20 +0200 |
On Wed, Aug 26, 2015 at 10:10 AM, Céline <address@hidden> wrote:
> Thank you for your help,
> But I really don't see how to apply this :/ (I'm quite a beginner...) Do I
> need to make another file with my function dX/dt=-J ?
> So I can write ("humsolide" is the name of my other .m file with this
> function):
> x=@(J) humsolide ?
> And then apply lsode ?
>
> Thank you,
>
> Céline
>
>
>
>
> --
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>
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Hi Céline,
1. Assume you have a function that retunrs the value fo J for a given time t
function Jvalue (t)
# content
endfunction
And then that the function defining the equations is
function dxdt = dynsys (x,t, J)
dxdt = -J(t);
endfunction
You can pass this to lsode as an anonymous function
func = @(x,t) dynsys(x,t, @Jvalue);
see more examples here
http://wiki.octave.org/Cookbook#Parametrized_Functions
2. You can also directly embed the J function within dynsys if it has
only one form, see the 2nd Demonstration of sigmoid_trian here
http://octave.sourceforge.net/signal/function/sigmoid_train.html
3. If the function J comes from data (that is you do ot have a
function of time, but only some finite values of it) you can use
datatofun http://octave.sourceforge.net/signal/function/data2fun.html
or you can write your own interpolation using interp1 (this is what
data2fun does check its code).
Good luck
- lsode use, Céline, 2015/08/25
- Re: lsode use, Doug Stewart, 2015/08/25
- Re: lsode use, Céline, 2015/08/25
- Re: lsode use, Olaf Till, 2015/08/25
- Re: lsode use, Céline, 2015/08/26
- Re: lsode use,
Juan Pablo Carbajal <=
- Re: lsode use, Céline, 2015/08/26
- Re: lsode use, Juan Pablo Carbajal, 2015/08/26
- Re: lsode use, Céline, 2015/08/26
- Re: lsode use, Juan Pablo Carbajal, 2015/08/26
- RE: lsode use, Pirson Céline, 2015/08/26
- Re: lsode use, Juan Pablo Carbajal, 2015/08/26
- Re: lsode use, Céline, 2015/08/26
- Re: lsode use, Juan Pablo Carbajal, 2015/08/26