Displaying 20 results from an estimated 2000 matches similar to: "unresolved symbols in dynamically linked code"
2004 Feb 05
1
Installing odesolve under MacOSX
Installing odesolve in Raqua 1.8.0 or 1.8.1 under MacOSX gives the following
message:
Warning message: Installation of package odesolve had non-zero exit status
in: install.packages(ui.pkgs, CRAN = getOption(where), lib = .libPaths()[1])
Moreover, in the source of odesolve is no makefile.
Does anyone know how to get a proper installation?
Maartje
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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2004 Sep 20
1
problem typcasting return of R_ExternalPtrAddr(SEXP s)
In the odesolve routine lsoda(), I allow the function (named func) that calculates the system of differential equations to be defined in a dll that has been dynamically loaded from the file named in dllname. I use getNativeSymbolInfo(func, dllname)$address to get the address of the function and pass it to a C function called via the .Call interface. Inside that C function, I use
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
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
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,
2006 Nov 21
1
f2c to achieve reentrancy in odesolve?
I am beginning a much-delayed update of odesolve to include several
ordinary differential equation solvers from the Livermore package
ODEPACK. These are much-used and reliable Fortran codes, and I plan (as
I did for lsoda in the current odesolve package) to make as few changes
as possible to the Fortran 77 code. However, recently someone wanted to
make nested calls to lsoda, which will not work,
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 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
2000 Aug 01
1
R_FindSymbol
I have written a function that uses LSODA from NETLIB to solve initial value
problems, given a system of ODEs written as an R function. There are times when
it would be convenient to use the code with an ode system written in a compiled
language. Certainly, that can be done using .C or .Fortran within an R
function, but that seems inefficient (indeed, it does not enormously speed up
the
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())
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
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
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:
2006 Nov 29
2
How to solve differential equations with a delay (time lag)?
Hi,
I would like to solve a system of coupled ordinary differential equations,
where there is a delay (time lag) term. I would like to use the "lsoda"
function "odesolve" package. However, I am not sure how to specify the
delay term using the syntax allowed by odesolve.
Here is an example of the kind of problem that I am trying to solve:
> library(odesolve)
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
2008 Mar 08
1
Installing odesolve package of R under Ubuntu (Debian) Linux
Bonjour,
Je cherche à installer le package odesolve du logiciel de statistique R sous
Ubuntu Linux.
C'est un package qui contient des fonctions appelant du code en Fortran.
A l'installation sous R via le shell, j'obtiens l'erreur suivante:
Hi,
I tried to install odesolve package of R under Ubuntu Linux.
But I got the following error:
ghislain@ghislain-laptop:~$ sudo R
[sudo]
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
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 <-
2003 Mar 06
2
question about model formula
Dear R Gang,
I'm interested in using R and the nls package for fitting kinetic
models. I'm having some difficulty getting a model specified for
nls though. The math for the model that I want to fit is
dg(t)/dt = K1 f(t) - k2 g(t)
where g(t) and f(t) are measured data at a sequence of times t.
K1 and k2 are the parameters of the model. If I solve this, the
solution is
g(t) = K1