similar to: using LSODA in R

Displaying 20 results from an estimated 300 matches similar to: "using LSODA in R"

2004 Jan 22
4
Fitting compartmental model with nls and lsoda?
Dear Colleagues, Our group is also working on implementing the use of R for pharmacokinetic compartmental analysis. Perhaps I have missed something, but > fit <- nls(noisy ~ lsoda(xstart, time, one.compartment.model, c(K1=0.5, k2=0.5)), + data=C1.lsoda, + start=list(K1=0.3, k2=0.7), + trace=T + ) Error in eval(as.name(varName), data) : Object
2006 Mar 13
2
winecfg fails to open X window
List serv subscribers, I am relatively new to Linux and of course this is my first time using Wine. I get this error message when trying to run winecfg: err:module:load_builtin_dll failed to load .so lib for builtin L"winex11.drv": libXxf86vm.so.1: cannot open shared object file: No such file or directory err:imagelist:ImageList_ReplaceIcon no color!
2011 Sep 30
1
need help with contourplot figure
I can't figure out how to add tick marks on both my X and Y axis. For example, my X axis ranges from 0 to 1 and there are both a tick mark and a number label at the X-axis values of 0.2,0.4,0.6. and 0.8. I want to add tick marks to the figure at every 0.1 value. This will help a viewer determine the values on the x axis. I included all of my code. I apologize but it is very long. I am
2004 Mar 13
2
recursive matrix multiplication question
List serv subscribers, I am wondering if there is an efficient means of doing recursive matrix multiplication in R. My data resides in a 4 X 2541 matrix from which I need to extract 2541 2X2 matrices based on each row. If I attempt something like this: function(AO) {A<-AO {for(t in 1:4)
2009 Oct 12
2
add=TRUE function not working
Hey everybody, I have a matrix with three columns. I want to plot two columns (independent variable) against one column (the defendant). This is my code and the error associated with it: plot(p, q, data=columns) > plot(pprime,q, add=TRUE) Warning messages: 1: In plot.window(...) : "add" is not a graphical parameter 2: In plot.xy(xy, type, ...) : "add" is not a graphical
2018 Oct 11
3
macOS Mojave: setgroups(501) failed: Too many extra groups
Hello, I have recently upgraded to macOS 10.14 (Mojave) and am running into an issue where one use can no longer log into dovecot via imap. Log shows Oct 11 08:10:27 imap(hwr)<12659><YpC/0+133+EAAAAAAAAAAAAAAAAAAAAB>: Fatal: setgroups(501) failed: Too many extra groups and indeed, the user is in 17 groups, which is more than NGROUPS_MAX (16). Another user with << 16 groups
2008 Apr 09
3
LSODA not accurate when RK4 is; what's going on?
I'm solving the differential equation dy/dx = xy-1 with y(0) = sqrt(pi/2). This can be used in computing the tail of the normal distribution. (The actual solution is y(x) = exp(x^2/2) * Integral_x_inf {exp(-t^2/2) dt} = Integral_0_inf {exp (-xt - t^2/2) dt}. For large x, y ~ 1/x, starting around x~2.) I'm testing both lsoda and rk4 from the package odesolve. rk4 is accurate using step
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
2008 Nov 21
1
lsoda warning "too much accuracy requested"
Dear list - Does anyone have any ideas / comments about why I am receiving the following warning when I run lsoda: 1: lsoda-- at t (=r1), too much accuracy requested in: lsoda(start, times, model, parms) 2: for precision of machine.. see tolsf (=r2) in: lsoda(start, times, model, parms) I have tried changing both rtol and atol but without success. I saw the thread in the
2005 Dec 05
1
how to save output all together
Dear R users: I have a problem about catch the value from function. I have following two functions (part): sbolus1 <- function() { ....... for( i in 1:Subject) { kel<-par1 Vd<-par2 PKindex<-sbolus1.out(PKtime,kel,Vd,defun,par1,par2,Dose,i) } savefile(PKindex) } sbolus1.out<-function(PKtime,kel,Vd,defun,par1,par2,Dose,i) { time<-PKtime$time
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:
2009 Dec 06
2
Error in eval(expr, envir, enclos) : object 'N' not found
I'm running an LSODA to generate some graphs, but I need to stop at a certain point and use those values to generate another LSODA output. This is working fine, but when I try to run the second LSODA, I get the "Error in eval(expr, envir, enclos) : object 'N' not found". Any ideas what can be causing this? I have no object 'N' anywhere in the script. I made an
2006 Aug 08
1
Fitting data with optim or nls--different time scales
Hi, I have a system of ODE's I can solve with lsoda. Model=function(t,x,parms) { #parameter definitions lambda=parms[1]; beta=parms[2]; d = parms[3]; delta = parms[4]; p=parms[5]; c=parms[6] xdot[1] = lambda - (d*x[1])- (beta*x[3]*x[1]) xdot[2] = (beta*x[3]*x[1]) - (delta*x[2]) xdot[3] = (p*x[2]) - (c*x[3]) return(list(xdot)) } I want
2012 Sep 06
2
choose() function returning anomalous results (zero instead of one)
Hello, (Apologies for length, wanted to get all the relevant detail in that I know of). I've been having a lot of trouble with some code for an inventory analysis problem I was doing, and finally came to the conclusion that it appears that choose() is returning incorrect values. Specifically: ------------- Browse[1]> nn [1] 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 3 3 3 3 3 3 3
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 Oct 06
1
Foreign code problem
Hello, I wanted to test the odesolve package and tried to use compiled C-code. But when I do: erg <- lsoda(y, times, "mond", parms, rtol, atol, tcrit=NULL, jacfunc=NULL, verbose=FALSE, dllname="mond", hmin=0, hmax=Inf) I get the error message: Error in lsoda(y, times, "mond", parms, rtol, atol, tcrit = NULL, jacfunc =
2004 Sep 06
1
A naive lsoda question....
Hello, I am an R newbie, trying to use lsoda to solve standard Lotka-Volterra competition equations. My question is: how do I pass a parameter that varies with time, like say, phix <- 0.7 + runif(tmax) in the example below. # defining function lotvol <- function(t,n,p){ x <- n[1]; y <- n[2] rx <- p["rx"]; ry <- p["ry"] Kx <-
2010 Sep 16
1
More accurate ODE solver?
Dear All, I was using rk4 and lsoda to solve a ODE system. However, both of them gave bad accurate solutions, especially compared with Matlab solver ODE45. For example, ODE45 gave solutions that can go to a stable level (about 1.6) when time goes to infinity, however, the solutions from lsoda are decreasing to very very small (about 1e-130) numbers. Does R have more accurate ODE solvers as
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())
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