Is possible to integrate this diferential equation: dN/dt = Nr(1-(N/K)) in R using the integrate() function? Or any other diferential equation? If yes, how? If no, anybody know any software on linux that make this? Inte Ronaldo -- O problema de ter os dois p??s bem firmes no ch??o ?? que voc?? n??o vai conseguir tirar as cal??as. --An??nimo -- |> // | \\ [***********************************] | ( ?? ?? ) [Ronaldo Reis J??nior ] |> V [UFV/DBA-Entomologia ] | / \ [36571-000 Vi??osa - MG ] |> /(.''`.)\ [Fone: 31-3899-2532 ] | /(: :' :)\ [chrysopa at insecta.ufv.br ] |>/ (`. `'` ) \[ICQ#: 5692561 | LinuxUser#: 205366 ] | ( `- ) [***********************************] |>> _/ \_Powered by GNU/Debian Woody/Sarge
"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.> Or any other diferential equation?Only if the right hand side does not depend on the dependent variable (N in this case) -- just plain integrals.> If yes, how? > > If no, anybody know any software on linux that make this?The "odesolve" package in R. Possibly, there's also stuff in Octave but I haven't looked lately. -- O__ ---- Peter Dalgaard Blegdamsvej 3 c/ /'_ --- Dept. of Biostatistics 2200 Cph. N (*) \(*) -- University of Copenhagen Denmark Ph: (+45) 35327918 ~~~~~~~~~~ - (p.dalgaard at biostat.ku.dk) FAX: (+45) 35327907
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>
I suggest that you check out the R package "odesolve" for solving
this.
However, from a more ecological standpoint (which I am guessing from the
fact that it is logistical growth) you might be interested in SOLVER.
You can find it at http://www.stams.strath.ac.uk/ecodyn/
Or indeed you might be interested in
http://www.stats.gla.ac.uk/~simon/simon/ddefit.html
Regards
Wayne Jones
-----Original Message-----
From: Ronaldo Reis Jr. [mailto:chrysopa@insecta.ufv.br]
Sent: 25 August 2004 21:02
To: R-Help
Subject: [R] integrate function
Is possible to integrate this diferential equation:
dN/dt = Nr(1-(N/K))
in R using the integrate() function?
Or any other diferential equation?
If yes, how?
If no, anybody know any software on linux that make this?
Inte
Ronaldo
--
O problema de ter os dois pés bem firmes no chão é que você não vai
conseguir
tirar as calças.
--Anônimo
--
|> // | \\ [***********************************]
| ( õ õ ) [Ronaldo Reis Júnior ]
|> V [UFV/DBA-Entomologia ]
| / \ [36571-000 Viçosa - MG ]
|> /(.''`.)\ [Fone: 31-3899-2532 ]
| /(: :' :)\ [chrysopa@insecta.ufv.br ]
|>/ (`. `'` ) \[ICQ#: 5692561 | LinuxUser#: 205366 ]
| ( `- ) [***********************************]
|>> _/ \_Powered by GNU/Debian Woody/Sarge
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