Re: [R] ODE

2018-04-12 Thread David Winsemius
You cross-posted this to StackOverflow (where there is already a response.) Cross-posting is viewed with scorn on both StackOverflow and Rhelp. > On Apr 12, 2018, at 1:36 PM, hudeyfa jama wrote: > > Hello All, > > > I'm struggling to solve this ODE using R, > > > vdpol <- function (h, v, t

[R] ODE

2018-04-12 Thread hudeyfa jama
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))

[R] ODE does not reach steady state and increase exponentially

2013-11-28 Thread Matteo Charlie Ichino
Dear all, please follow the link to the question that I posted on StackOverflow about my R code with ODE http://stackoverflow.com/questions/20218065/ode-does-not-reach-steady-state-and-increase-exponentially I am trying to write a code for a differential equation that should give me the biomass of

Re: [R] Ode error message

2013-07-16 Thread Berend Hasselman
See inline remarks. On 16-07-2013, at 10:07, Raphaëlle Carraud wrote: > Hello, > > I am creating a program with R to solve a differential equation system. > However, I get the following message I do not understand : > >> out <- ode(y = state, times = z, func = liquide, parms = 0, atol = 0)

[R] Ode error message

2013-07-16 Thread Raphaëlle Carraud
Hello, I am creating a program with R to solve a differential equation system. However, I get the following message I do not understand : > out <- ode(y = state, times = z, func = liquide, parms = 0, atol = 0) DLSODA- EWT(I1) is R1 .le. 0.0 In above message, I1 = 1 In above message, R1 = 0

Re: [R] ODE solver

2013-05-02 Thread Thomas Petzoldt
Hi, just press ESC and the solver should stop. BTW, warnings like this are usually a sign of unrealistic parameters, problematic model equations or inappropriate tolerance settings. See also: http://cran.r-project.org/web/packages/deSolve/vignettes/deSolve.pdf#46 ThPe On 5/2/2013 10:36 AM,

Re: [R] ODE solver

2013-05-02 Thread William Dunlap
rom: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] On > Behalf > Of David Winsemius > Sent: Thursday, May 02, 2013 7:22 AM > To: Tjun Kiat Teo > Cc: r-help@r-project.org > Subject: Re: [R] ODE solver > > > On May 2, 2013, at 1:36 AM, Tjun Kia

Re: [R] ODE solver

2013-05-02 Thread David Winsemius
On May 2, 2013, at 1:36 AM, Tjun Kiat Teo wrote: > 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. >

[R] ODE solver

2013-05-02 Thread Tjun Kiat Teo
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 an

[R] ode() tries to allocate an absurd amount of memory

2012-02-04 Thread Karline Soetaert
ynamic-models that deals with this type of questions. Original message: Date: Fri, 3 Feb 2012 09:33:05 -0500 From: Thomas Brown mailto:thomasbrown8...@gmail.com>> To: r-help@r-project.org<mailto:r-help@r-project.org> Subject: [R] ode() trie

[R] ode() tries to allocate an absurd amount of memory

2012-02-03 Thread Thomas Brown
Hi there R-helpers: I'm having problems with the function ode() found in the package deSolve. It seems that when my state variables are too numerous (>33000 elements), the function throws the following error: Error in vode(y, times, func, parms, ...) : cannot allocate memory block of size 13743

[R] ode() tries to allocate an absurd amount of memory

2012-01-30 Thread Thomas Brown
Hi there R-helpers: I'm having problems with the function ode() found in the package deSolve. It seems that when my state variables are too numerous (>33000 elements), the function throws the following error: Error in vode(y, times, func, parms, ...) : cannot allocate memory block of size 13743

Re: [R] ode first step

2009-05-17 Thread Benoit Boulinguiez
} data<-seq(1.5,2.1,,100) plot(data,sapply(data,SSD),type="l") -- Regards/Cordialement Benoit Boulinguiez -Message d'origine- De : spencerg [mailto:spencer.gra...@prodsyse.com] Envoyé : vendredi 15 mai 2009 05:28 À : Benoit Boulinguiez

Re: [R] ode first step

2009-05-14 Thread spencerg
nt known values. Nevertheless, I still get this 'Error about object 'K1' not found'. Regards/Cordialement Benoit Boulinguiez -Message d'origine- De : Dieter Menne [mailto:dieter.me...@menne-biomed.de] Envoyé : jeudi 14 mai 2009 12:12 À : 'Benoit Boulingu

Re: [R] ode first step

2009-05-14 Thread Benoit Boulinguiez
rs and {C0,m,V} are constant known values. Nevertheless, I still get this 'Error about object 'K1' not found'. Regards/Cordialement Benoit Boulinguiez -Message d'origine- De : Dieter Menne [mailto:dieter.me...@menne-biomed.de] Envoyé : jeudi 14 mai 2009 12:1

Re: [R] ode first step

2009-05-13 Thread Dieter Menne
Benoit Boulinguiez ensc-rennes.fr> writes: > I try to assess the parameters (K1,K2) of a model that describes the > adsorption of a molecule onto on adsorbent. > > equation: dq/dt = K1*C*(qm-q)-K2*q > > I know the value of 'qm' and I experimentally measure the variables 'q', > 'C', and the time

[R] ode first step

2009-05-13 Thread Benoit Boulinguiez
Hi all, I try to assess the parameters (K1,K2) of a model that describes the adsorption of a molecule onto on adsorbent. equation: dq/dt = K1*C*(qm-q)-K2*q I know the value of 'qm' and I experimentally measure the variables 'q', 'C', and the time 't'. t C q 1 0 144.0