similar to: ODE solvers in R (was:The Wrong Choice: Locked in by license restrict...

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

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

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

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

We are currently implementing the backends for other solvers (you can follow the progress here: https://github.com/mikhailramalho/clang). So far we got Boolector, MathSAT and Yices ready. CVC4 should be done soon. When used to refute bugs, they all give roughly the same results: a ~5% speedup if there are refuted bugs or a ~5% slowdown if no bug is refuted. I've only tried to analyze one

Hi all, Currently studying the impact of SMT solvers on Clang SA. Can anyone help in telling more about the SMT solvers use in clang SA ? ( Have already tested Z3 SMT solver implemented in GSoC 2018 , also looking for other SMT solvers if possible ) Thanks, Siddharth -------------- next part -------------- An HTML attachment was scrubbed... URL:

I am trying to use the package ode and periodically it will come up with this error message Warning..Internal T (=R1) and H (=R2) are such that in the machine, T + H = T on the next step (H = step size). Solver will continue anyway. And then the program just take very long to run. Is there anyway to get the program to terminate when this warning is issued instead of continuing to run ?

Hi, I did some googling. I found multiple ODE solver packages. But I am wondering if there is any terminal value ODE solver (linear case) for multi-dimension case or not? I have not come across any. Any guidance would be appreciated. Robert [[alternative HTML version deleted]]

We are running Centos 5.6. All was fine until yesterday. I attempted to tar a 14KB work file to a USB floppy (/dev/sdb) for transport to another server. Unfortunately, I keyed in 'tar cvf /dev/sda filename' instead of 'tar cvf /dev/sdb filename'. /dev/sda is our main (boot/root/apps) scsi hard drive. I realized my mistake, but it was too late. The system is still

I just joined the list and appologize if this has been answered before but I am trying to interface between R and the Compaq Visual Fortran compiler version 6.6 for Windows. I found the following instructions on the web -- and an example. When I follow these directions exactly. R 2.0.0 crashes. Has anyone had any experience with this? Below are the instructions that I located: Thanks Dan

Dear list The deSolve package allows you to specify the model code in C or Fortran. Thanks to the excellent vignette this works fine. However I have not yet managed to use forcing functions in C code. In pure R code this works very well with approxfun() specified outside the model: ############################################### #Model lvml <- function(t, x, parms) {

Hi All, I need to write a script that I will manually start (or a cron job in future) but I need it to do a number of things in order one after another. How do i do that so everything gets dont as the steps depend on each other. Example: cd /system_backups/ tar cvf apache-conf.tar /etc/httpd/conf/* gzip -v9 apache-conf.tar tar cvf apache-data.tar /var/www/* gzip -v9 apache-data.tar

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 <-

I've done a decent size update of the OpenSSH portable from the upstream tree. There is an AES upgrade that needs to take place, but I need people to test and tell me what endedness changes need to be applied (if any). Attached is the patch. It is geared towards the latter snapshots..Unsure how it will patch (if at all) against 2.9pX series. Thanks. - Ben "This is dark day in

Hi [1.] One line summary of the problem: rsync segfaulting and the kernel oops'ing while synchronizing two smbfs's [2.] Full description of the problem/report: I am implementing file synchronization between two Windows NT 4 machines through two smbfs mounts. Rsync runs for about half an hour; then the kernel gives an oops and rsync segfaults. Hereafter the smbfs file system is

Hi. Is there such a limit to 2GB in samba 2.2.8a-1? I get a "File imit exceeded" when I try to tar or cp smth to a smbmount. On both machines I can successfully do dd if=/dev/zero and create a file of 3GB, I can also tar -cvf it but no cp to smb. RH8 if it matters...

Hi Using tar i normally create an archive etc and then unpack that archive, job done. But i am copying from one filesystem to another on the same host, they are 2 seperate nfs filesystems, and i wonder is it possible to use tar to do this as opposed to say rsync etc. tar -cvf /some/input/dir to/here etc ? thanks

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

Hi all, I study epidemiology of soilborne disease. I have this ode model dS/dt = - (rp(t) X + rs(t) I) * S with X=1 ; rp(t) = ap exp( - bp*t) ; rs(t) = as exp (-0.5 ( ln (t/ds) / bs)? ) The data I have are not directly the infected individuals (which is a hidden state) but the Diseases ones (individuals who show aerial symptoms). I have studied with experiments the relationship between the

Hello All, I'm struggling to solve this ODE using R, vdpol <- function (h, v, t) ( list(c ( -0.1*v/(pi*(2*10*h-h^2)), (v = (-0.1*v/(pi*(2*10*h-h^2))^2) + 2*9.81*h)) )) library(deSolve) yini <- (c(h = 20, v=0)) nonstiff <- ode(y = yini, func = vdpol, times= seq(0, 30, by =