[R] integrate function

Jari Oksanen jarioksa at sun3.oulu.fi
Thu Aug 26 11:55:49 CEST 2004

On Wed, 2004-08-25 at 23:44, Peter Dalgaard wrote:
> "Ronaldo Reis Jr." <chrysopa at insecta.ufv.br> writes:
> > Is possible to integrate this diferential equation:
> > 
> > dN/dt = Nr(1-(N/K))
> > 
> > in R using the integrate() function?
> No.
However,  you could use 

N = K/(1 + exp(log((K-N0)/K) -r*t)),

where N0 is the population size at t=0 (that you must fix or estimate).

Causton has a long discussion about integrating this funcition on in his
"Mathematics for Biologists" (or something like that). Apart from that
MuPad may be free for Linux, and you can buy many other alternatives for
symbolic mathematics (Maple is available for Linux, at least). It may be
that you still have to work to get the solution you need, even with
snappy tools like that.

cheers, jari oksanen
Jari Oksanen <jarioksa at sun3.oulu.fi>

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