Displaying 20 results from an estimated 2000 matches similar to: "f2c to achieve reentrancy in odesolve?"
2000 Nov 17
1
Ordinary differential equations in R?
Is there any R code available for solving ODE's? I am considering building
an interface to ODEPACK, but don't want to duplicate any existing effort.
--
Tom Wainwright
NOAA/NMFS/NWFSC
2030 S Marine Science Dr
Newport, OR 97365 USA
thomas.wainwright at noaa.gov
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2002 Feb 01
1
typo and user-proofing in odesolve() (PR#1295)
A couple of minor points about the odesolve package
(which I am otherwise enjoying very much):
1. "scalar" is misspelled as "scaler" in the definitions of
the rtol and atol parameters
2. it is possible to crash R by doing something dumb, e.g
failing to read the documentation carefully enough and (a)
returning only a vector of derivatives and not a list of
(derivatives,
2004 Jun 10
2
odesolve: lsoda vs rk4
I'm trying to use odesolve for integrating various series of coupled 1st
order differential equations (derived from a system of enzymatic
catalysis and copied below, apologies for the excessively long set of
parameters).
The thing that confuses me is that, whilst I can run the function rk4:
out <- rk4(y=y,times=times,func=func, parms=parms)
and the results look not unreasonable:
2005 Jul 27
4
odesolve/lsoda differences on Windows and Mac
Hi -
I am getting different results when I run the numerical integrator
function lsoda (odesolve package) on a Mac and a PC. I am trying to
simulating a system of 10 ODE's with two exogenous pulsed inputs to the
system, and have had reasonably good success with many model parameter
sets. Under some parameter sets, however, the simulations fail on the
Mac (see error message below). The
2005 Nov 14
1
(no subject)
Hi,
I am trying to solve a model that consists of rather stiff ODEs in R.
I use the package ODEsolve (lsoda) to solve these ODEs.
To speed up the integration, the jacobian is also specified.
Basically, the model is a one-dimensional advection-diffusion problem,
and thus the jacobian is a tridiagonal matrix.
The size of this jacobian is 100*100.
In the original package
2003 May 27
3
The Wrong Choice: Locked in by license restrictions
A colleague pointed me to this article advocating R as a Matlab
substitute. Here is the link (deliberately on two lines:
http://searchenterpriselinux.techtarget.com/
originalContent/0,289142,sid39_gci902076,00.html
I'm not a Matlab user, but I understand that it provides a nice front
end to the Linpack collection of numerical linear algebra routines. My
friend and I wonder if R can really
2000 Jul 26
4
differential equations
Hi, Does somebody knows of the existence of a library of functions
for solving differential equations, I need a solver for a system of non
linear first order differential equations. I think there was something
in IMSL but that was a long time ago and probably there are some
new algorithms in the new now.
Thanks for any pointers.
.
R. Heberto Ghezzo Ph.D.
Meakins-Christie Labs
McGill
2009 Jun 29
0
new version of package deSolve on CRAN
Dear R users,
an improved version of package deSolve (version 1.3) is now available on
CRAN. deSolve, the successor of R package odesolve, is a package to
solve initial value problems (IVP) of:
- ordinary differential equations (ODE),
- differential algebraic equations (DAE) and
- partial differential equations (PDE).
The implementation includes stiff integration routines based on the
ODEPACK
2009 Jun 29
0
new version of package deSolve on CRAN
Dear R users,
an improved version of package deSolve (version 1.3) is now available on
CRAN. deSolve, the successor of R package odesolve, is a package to
solve initial value problems (IVP) of:
- ordinary differential equations (ODE),
- differential algebraic equations (DAE) and
- partial differential equations (PDE).
The implementation includes stiff integration routines based on the
ODEPACK
2000 Apr 15
2
unresolved symbols in dynamically linked code
I'm probably misunderstanding something in "Writing R Extensions" version
1.0.0. In the chapter on the R API, section 4.7, it is stated that the
functions listed in R_ext/Linpack.h are available to users' Fortran code.
I am developing a developing a library of ode solvers, based on lsoda and
ddassl, and which in turn call some routines from linpack and double
precision blas. I
2006 Jul 28
1
odesolve loading problem
Hi,
I get the following error message when loading the package odesolve ( R
2.2.1 - odesolve 0.5.14 - AMD64 - Linux Fedora Core 4 ) :
> library(odesolve)
Error in library.dynam(lib,package,package.lib) :
shared library 'TRUE' not found
Error: package/namespace load failed for 'odesolve'
Any help would be greatly appreciated
Ariel./
2005 Oct 25
2
solving ODE's in matrix form with lsoda()
Hello there,
Suppose you want to solve the following system of ODE's (a simple
Lotka-Volterra predator prey model)
dP/dt = beta*P*V - mu*P
dV/dt = r*V - beta*P*V
where P and V are the numbers of predators and prey. Now, this is
easy to do, but suppose you have a system of equations like this,
dP1/dt = beta1*P1*V1 - mu1*P1
dP2/dt = beta2*P2*V2 - mu2*P2
dV1/dt = r1*V1 - beta1*P1*V1
2001 May 11
1
lsoda
I am running R 1.2.3 with ESS5.1.18 with Windows 98.
I am trying to use lsoda in the odesolve apckage and am having problems.
Question:
The return value of the function of the system of ode's has to be a list
that includes first, the ode's and second, "a vector
(possibly with a `names' attribute) of global values that are
required at each point in `times'."
I
2001 Sep 11
2
Differential Equations Using R?
To whom it may concern,
I am a student at Macaleste College, and next semester Macalester
is going to offer a course for CellBio that is mainly statistically based.
For the most part the students will be using R for analysis. The problem is
there will be some simple differential equations for the students to solve.
The committee that in charge of the classes corriculam would like only to
2001 May 09
3
odesolve check fails
Hi,
I just installed the odesolve package and ran the check command on it. It
failed trying to execute
library(gnlm).
Sure enough, there is no gnlm library on my system and I could not find it
on the CRAN archive either. Am I missing anything obvious or is gnlm some
private library that somehow found its way into the example section of
odesolve?
Thanks in advance,
Andy
2008 Sep 16
2
odesolve dynload example
Hello R Developers,
This is my first foray into using c-code with R, so please forgive my
foolishness.
I had a look at the archives and did not find anything on this, so
hopefully I am not doubling up.
I have tried to use R cmd to create an object file from the odesolve
dynload example.
I am using windows and have just installed rtools, and have the latest
version of stable R (2..7.2).
This is
2005 Nov 06
1
Problem defining a system of odes as a C library with lsoda
I have been trying to make use of the odesolve library on my
university's Linux grid - currently R version 2.0.1 is installed and
the system runs 64-bit Scientific Linux based on Redhat. I cannot seem
to get lsoda working when I define the model as a shared C library. For
example, the following snippet uses the mymod.c example bundled with
the package:
### START
rm(list=ls())
2010 Apr 06
1
estimating the starting value within a ODE using nls and lsoda
All-
I am interested in estimating a parameter that is the starting value for an ODE model.
That is, in the typical combined fitting procedure using nls and lsoda (alternatively rk4), I first defined the ODE model:
minmod <- function(t, y, parms) {
G <- y[1]
X <- y[2]
with(as.list(parms),{
I_t <- approx(time, I.input, t)$y
dG <- -1*(p1 + X)*G +p1*G_b
dX <-
2005 Oct 26
2
changing memory limits to speed up lsoda
Hi All,
I am running R 2.2.0 on Mac OS 10.4.2, dual G5 processors with 8 Gig
RAM.
I am running a simulation with lsoda that requires ~378 s to complete
one set of time intervals. I need to optimize the parameters, and so
need to considerably speed up the simulation.
I have tried to figure out how to change the appropriate memory
allocation and have search R help and Introductory
2007 Jun 06
3
Using odesolve to produce non-negative solutions
Hello,
I am using odesolve to simulate a group of people moving through time and transmitting infections to one another.
In Matlab, there is a NonNegative option which tells the Matlab solver to keep the vector elements of the ODE solution non-negative at all times. What is the right way to do this in R?
Thanks,
Jeremy
P.S., Below is a simplified version of the code I use to try to do this,