similar to: specify a model in differential equations (nlme)

Hello! I would like to know if R can solve Differential Equations... I don't think so because, in my point, I see R like a Statistical System, not a Math System. Am I wrong? Thank you very much. M??rcio de Medeiros Ribeiro Graduando em Ci??ncia da Computa????o Departamento de Tecnologia da Informa????o - TCI Universidade Federal de Alagoas - UFAL Macei?? - Alagoas - Brasil Projeto CoCADa

Hello list I have a theoretical differential equation model (two coupled differential equations) describing the acidification of dairy cultures in milk: dX/dt = f(H, param)*X dH/dt = g(param)*dX/dt pH = -log10(H) I also have actual data of the same. I would like to estimate the parameters of the theoretical model from real data, but don't know how to go about it in R (I'm fairly new

Hello, I want to know if there are some functions or packages to solve differential and integral equation using R. Thanks. Shao chunxuan. [[alternative HTML version deleted]]

Dear All A new non-linear mixed-effects modelling package for R called nlmeODE is now available at www.cran.r-project.org and http://nlmeODE.sourceforge.net. It combines Pinheiro and Bates' NLME library in R with an ordinary differential equations (ODE) solver thereby enabling the use of differential equations in population PK/PD modelling. It includes several PK examples such as one- and

Dear all, I have two questions: 1. Does anyone know if nlmeODE package will work once odesolve is discontinued? If i understand well nlmeODE depends on odesolve. 2. Can anyone suggest another package I could use to fit complex PKPD models (described using differential equations) to data? Thanks a lot! Magdalena

Hello List, Can you recommend me if odeSolve can handle stiff delay differential equations with discontinuities? Or any other package? Best, -m

I need to solve a system of non-linear fourth-order differential equations. Is there a command which solves this system? Thanks in advance.

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

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)

e1 <- function(x,b,t){ d<-(x)*(b^t) plot(d) } e1(2, 2,seq(from=0, to=6, by=1)) Is there a way to do this with a change in time. I would like to use differential equations. I am trying to model a population with an initial value, fecundity per time step, and a death rate. The above simply shows an exponential growth rate. I would like to model species response like the famous

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

Hello everyone, I am trying to solve 2D differential equations using finite difference scheme in R. I have been able to work with the equations with only one spatial dimensions but I want to extend it to the two dimensional problem. For example i can simulate one dimensional diffusion using a code like the following. But I want to write a similar code for,say, a two dimensional diffusion

Dear list, I want to show all the objects starting with "d" and ending with a digit. How do I specify these conditions in the pattern argument I can do one condition but not two ls(pattern='^d') ls(pattern='[[:digit:]]$') are working. But, ls(pattern='^d'&'[[:digit:]]$') is not working. Appreciate any comment. Jun Shen [[alternative HTML

Dear R-users, I am trying to perform some simulations from a model defined by ordinary differential equations. I would be grateful if someone could indicate some functions/packages/examples I could look at. Thank you in advance. Sebastien

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 -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read

Hello, I am developing an agent-based model to simulate the spread of infectious diseases in heterogeneous landscapes composed of habitat polygons (or clumps of connected cells). To simplify the model, I consider a habitat grid (or raster) containing the polygon ID of each cell. In addition, I have epidemiological parameters associated with each polygon ID. At each time step, the parameter values

Hi all, My apologies if this message is incredibly inept but I am very new to both computer programming and to R. I am working with the odesolve add-on and have the following function defined RVF_Single <- function(t, x, p) within the script I also have the following functions defined: T1<-function(t) {T1<-27.5-12.5*cos(2*pi*t/365)} and B1<-function(T1,t)

John, thanks for your helpful advice. My ultimate goal is to construct a full instruction-level program dependence graph for a given IR file. The hard point is how to establish the correct data dependence edges when some function arguments are multi-level pointers. To solve this problem I hope to check the point-to level for each pointer variable. I think the data dependence through pointers can

John, thanks for you answer! But as far as I know LLVM doesn't provide any interface for finding the pointee of a pointer directly, so i have to process a multi-level pointer i need to write my own function to check pointers level by level, is that right? On Fri, Jul 17, 2015 at 1:47 PM, John Criswell <jtcriswel at gmail.com> wrote: > On 7/17/15 12:38 PM, Shen Liu wrote: > >

I am an initial user of R. Could you give me some explanations or examples on how to solve the first order differential equations by the first-order Runge-Kutta method? Thank you very much Kind regards