search for: ode

Displaying 20 results from an estimated 345 matches for "ode".

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2017 Jun 21
4
How to apply a system of ordinary differential equations to a cell grid?
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...
2010 Dec 23
0
epidemiology ode likelihood, hierarchical model
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 wi...
2018 Apr 12
1
ODE
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, fun...
2018 Apr 18
2
Event-triggered change in value with a time-delay
Hello, I am solving a set of ODEs using deSolve and have run into a problem I would appreciate some advice on. One of the parameters (m) in the ODEs changes between two states when one of the variables (D) crosses a threshold (D_T) for the first time in either direction. Additionally, when the variable crosses the threshold (eithe...
2017 Jul 10
4
fit lognorm to cdf data
...th lognorm function but maybe somebody already solved such task. Best regards Petr ________________________________ Tento e-mail a jak?koliv k n?mu p?ipojen? dokumenty jsou d?v?rn? a jsou ur?eny pouze jeho adres?t?m. Jestli?e jste obdr?el(a) tento e-mail omylem, informujte laskav? neprodlen? jeho odes?latele. Obsah tohoto emailu i s p??lohami a jeho kopie vyma?te ze sv?ho syst?mu. Nejste-li zam??len?m adres?tem tohoto emailu, nejste opr?vn?ni tento email jakkoliv u??vat, roz?i?ovat, kop?rovat ?i zve?ej?ovat. Odes?latel e-mailu neodpov?d? za eventu?ln? ?kodu zp?sobenou modifikacemi ?i zpo?d?n?m...
2017 Jul 04
6
R and UBUNTU startup
...some kind of "Linux R for Windows dummies" available? Best regards Petr ________________________________ Tento e-mail a jak?koliv k n?mu p?ipojen? dokumenty jsou d?v?rn? a jsou ur?eny pouze jeho adres?t?m. Jestli?e jste obdr?el(a) tento e-mail omylem, informujte laskav? neprodlen? jeho odes?latele. Obsah tohoto emailu i s p??lohami a jeho kopie vyma?te ze sv?ho syst?mu. Nejste-li zam??len?m adres?tem tohoto emailu, nejste opr?vn?ni tento email jakkoliv u??vat, roz?i?ovat, kop?rovat ?i zve?ej?ovat. Odes?latel e-mailu neodpov?d? za eventu?ln? ?kodu zp?sobenou modifikacemi ?i zpo?d?n?m...
2018 Feb 08
2
plotting the regression coefficients
...rg mailing list -- To UNSUBSCRIBE and more, see > > https://stat.ethz.ch/mailman/listinfo/r-help > > PLEASE do read the posting guide http://www.R-project.org/ > posting-guide.html > > and provide commented, minimal, self-contained, reproducible code. > > ________________________________ > Tento e-mail a jak?koliv k n?mu p?ipojen? dokumenty jsou d?v?rn? a jsou > ur?eny pouze jeho adres?t?m. > Jestli?e jste obdr?el(a) tento e-mail omylem, informujte laskav? > neprodlen? jeho odes?latele. Obsah tohoto emailu i s p??lohami a jeho...
2009 May 13
2
ode first step
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 0 144.05047 0.0000000 2 56...
2017 Jul 11
1
fit lognorm to cdf data
...; > Best regards > > Petr > > > > ________________________________ > > Tento e-mail a jak?koliv k n?mu p?ipojen? dokumenty jsou d?v?rn? a jsou > ur?eny pouze jeho adres?t?m. > > Jestli?e jste obdr?el(a) tento e-mail omylem, informujte laskav? neprodlen? > jeho odes?latele. Obsah tohoto emailu i s p??lohami a jeho kopie vyma?te ze > sv?ho syst?mu. > > Nejste-li zam??len?m adres?tem tohoto emailu, nejste opr?vn?ni tento email > jakkoliv u??vat, roz?i?ovat, kop?rovat ?i zve?ej?ovat. > > Odes?latel e-mailu neodpov?d? za eventu?ln? ?kodu zp?sobe...
2018 Feb 08
2
plotting the regression coefficients
...rg mailing list -- To UNSUBSCRIBE and more, see > > https://stat.ethz.ch/mailman/listinfo/r-help > > PLEASE do read the posting guide http://www.R-project.org/ > posting-guide.html > > and provide commented, minimal, self-contained, reproducible code. > > ________________________________ > Tento e-mail a jak?koliv k n?mu p?ipojen? dokumenty jsou d?v?rn? a jsou > ur?eny pouze jeho adres?t?m. > Jestli?e jste obdr?el(a) tento e-mail omylem, informujte laskav? > neprodlen? jeho odes?latele. Obsah tohoto emailu i s p??lohami a jeho...
2018 Feb 10
0
plotting the regression coefficients
Hi Peter; The R code you provided works very well. Once again thanks so much for this. The number of variables in my data set that should appear on the y-axis is 733 and they are not numerical (for example the name of one variable is *palmitoyl-arachidonoyl-glycerol (16:0/20:4) [1]**. So, the plot looks very messy...
2018 Feb 08
0
plotting the regression coefficients
...lp at r-project.org> mailing list -- To UNSUBSCRIBE and more, see > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. ________________________________ Tento e-mail a jak?koliv k n?mu p?ipojen? dokumenty jsou d?v?rn? a jsou ur?eny pouze jeho adres?t?m. Jestli?e jste obdr?el(a) tento e-mail omylem, informujte laskav? neprodlen? jeho odes?latele. Obsah tohoto emailu i s p??lohami a jeho kopie vyma?te ze sv?ho syst?...
2011 Mar 15
1
precompiled ode with spline input
I tried to use lsode with precompiled C code instead of an R function defining the derivatives. No problem so far. However, now I need to implement an ODE that contains spline functions, i.e. the derivatives at given time points depend on the value of a spline function at this time point. What is an efficient way to i...
2012 Apr 27
0
How to find eigenfunctions and eigenvalues of a fourth order ODE
Dear all, I am having trouble with the following problem. Suppose we have the fourth order ODE with boundary conditions: http://r.789695.n4.nabble.com/file/n4591748/problem.jpg problem.jpg where q(t) is a known function. Note here the lambda parameter is changing, so essentially we have a series of ODEs. lambda is called an eigenvalue, the solution y is called an eige...
2018 Feb 12
2
plotting the regression coefficients
...(reshape2) library(ggplot2) temp <- melt(temp) temp.s<-split(temp, cut(1:nrow(temp), 2)) pdf("temp.pdf") for (i in 1: length(temp.s)) { p <- ggplot(temp.s[[i]], aes(x=par1, y=variable, size=abs(value), colour=factor(sign(value)))) print(p+geom_point()) } dev.off() But the real code partly depends on your real data. Cheers Petr From: greg holly [mailto:mak.hholly at gmail.com] Sent: Saturday, February 10, 2018 9:05 PM To: PIKAL Petr <petr.pikal at precheza.cz> Cc: r-help mailing list <r-help at r-project.org> Subject: Re: [R] plotting the regression coefficients...
2017 Jul 04
0
R and UBUNTU startup
...some kind of "Linux R for Windows dummies" available? Best regards Petr ________________________________ Tento e-mail a jak?koliv k n?mu p?ipojen? dokumenty jsou d?v?rn? a jsou ur?eny pouze jeho adres?t?m. Jestli?e jste obdr?el(a) tento e-mail omylem, informujte laskav? neprodlen? jeho odes?latele. Obsah tohoto emailu i s p??lohami a jeho kopie vyma?te ze sv?ho syst?mu. Nejste-li zam??len?m adres?tem tohoto emailu, nejste opr?vn?ni tento email jakkoliv u??vat, roz?i?ovat, kop?rovat ?i zve?ej?ovat. Odes?latel e-mailu neodpov?d? za eventu?ln? ?kodu zp?sobenou modifikacemi ?i zpo?d?n?m...
2017 Jul 10
0
fit lognorm to cdf data
...ody already solved such task. > > Best regards > Petr > > ________________________________ > Tento e-mail a jak?koliv k n?mu p?ipojen? dokumenty jsou d?v?rn? a jsou ur?eny pouze jeho adres?t?m. > Jestli?e jste obdr?el(a) tento e-mail omylem, informujte laskav? neprodlen? jeho odes?latele. Obsah tohoto emailu i s p??lohami a jeho kopie vyma?te ze sv?ho syst?mu. > Nejste-li zam??len?m adres?tem tohoto emailu, nejste opr?vn?ni tento email jakkoliv u??vat, roz?i?ovat, kop?rovat ?i zve?ej?ovat. > Odes?latel e-mailu neodpov?d? za eventu?ln? ?kodu zp?sobenou modifikacemi ?i...
2017 Aug 01
0
Superscript and subscrib R for legend x-axis and y-axis and colour different subjects in longitudinal data with different colours
...g like plot(c(1:5), CRP7raw[1,], type = "n", xlim=c(1,5), ylim=c(-10,5) , > xlab="Day in ICU", > ylab="CRP (mg/dL)", > sub = mtext(expression(lambda^2))) OOps! Either plot( ..., sub = *) or plot( ... ) ; mtext(*) but not both! You are right, I used a code from OP and did not much think about it. Strangely enough, the code worked without any complain. Probably mtext is "stronger" than sub and overrides it. Well, well, "the magic of R" ..... Not quite: mtext(..) is a valid function call that is evaluated before plot() finishes;...
2017 Jul 17
0
How to apply a system of ordinary differential equations to a cell grid?
It seems that the method `iteration` in the function `ode` can be useful in my case: > Method "iteration" is special in that here the function func should > return the new value of the state variables rather than the rate of > change. This can be used for individual based models, for difference > equations, or in those cases where t...
2018 Apr 18
0
Event-triggered change in value with a time-delay
> On Apr 18, 2018, at 1:04 AM, Hannah Meredith <hrmeredith12 at gmail.com> wrote: > > Hello, > > I am solving a set of ODEs using deSolve and have run into a problem I > would appreciate some advice on. One of the parameters (m) in the ODEs > changes between two states when one of the variables (D) crosses a > threshold (D_T) for the first time in either direction. Additionally, when > the variable crosses...