similar to: Solution to differential equation for nls function

Hello, I am trying to find the analytical solution to this differential equation dR/dt = k1*(R^k2)*(1-(R/Rmax)); R(0) = Ro k1 and k2 are parameters that need to fitted, while Ro and Rmax are the baseline and max value (which can be fitted or fixed). The response (R) increases initially at an exponential rate governed by the rate constants k1 and k2. Response has a S-shaped curve as a function

Hello, I am trying to compute the density of a variable k that is either (1) Normally distributed; (2) Log-Normally distributed; or (3) follows proportional error distribution. I tried to search R-help and the answer for normal distribution was easy to find (please see 1c). I am not sure if my formula for dlnorm is correct (please see 2c below)? I really don't know what function to use for the

Hello, I am trying to add a less than equal to symbol in a ggplot2 legend text. See sample code below. I have tried using the expression function and \u2264. I also tried adding labels to legend.text under theme. Neither of these 3 options work. Please help, Mahesh ++++++++++++++ Extra.column=ifelse(data[,covariate]>cutpoint,1,0) Grp1 <- "\u2264 1.5" Grp2 <-

Hello, I am trying to use ≥ symbol in the Trellis custom strip. The ascii ALT Key for this symbol is 242. However, when I try "\242 90 kg" I get the ¢ symbol in the trellis custom strip. Can some one kindly help me? Thanking you in advance, MNS [[alternative HTML version deleted]]

Hi, I would like to plot the following equation: dF(x)/dx=(k1+k2F(x))(1-F(x)) where k1 and k2 are parameters that I have estimated already. How can I plot the curve in R? Thanks! Montserrat Rue Universitat de Lleida (Spain) [[alternative HTML version deleted]]

Hi, I'd like to know whether R is capable to assess parameters in a model describing the kinetic of a pollutant adsorption onto activated carbon. A common relation is for instance the Adam-Bohart-Thomas' one: dx/dt = K1 * (qm-x)*C - K2x where {K1,K2} are the unknown paramters and {qm,C} are known parameters Of course I get experimental data sets of measured x as a function of time.

Hello, I am a new R user having transitioned over from S-plus recently. I have a question that is probably very trivial but I am having trouble finding a solution. In S-plus, graphic pages are created as tabs when multi-page figures are created. I have shown the R code for xpose.VPC (a function within library xpose4 for R) where I want the figure from each Strata (STRT) to displayed on a

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)

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

This is applicable to either using optim or the differential equation solver or any similar solver Suppose I want to use the differential equation solver and this is my code d<-y[2] vdpol<-function(t,y) { list(c(1, d, 3, 4 ) } stiff<-ode(y=rep(0,4),times=c(0,1),func=dvdpol,parms=1) The thing is I want d to be composed of one of state variables in the

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

i am trying to solve a partial differential equation analytically(PDE) in R . i have found some functions that do the stuff numerically. But that will not meet my purpose. is there any function to solve PDE analytically. please help. -- View this message in context: http://r.789695.n4.nabble.com/analytical-solution-of-partial-differential-equation-tp4291618p4291618.html Sent from the R help

I haven't used r in quite a while but would like to get back into it. I have a problem that I would like to solve with r. I have some multinomial data that looks to follow an asymmetric sigmoidal growth pattern. Solving a multinomial gompertz partial differential equation in r is what I’m after. Would anyone be able to provide me the code and packages to do something like this? Regards,

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

I'm trying to write differential equations into R code. Can anyone help me with the following equation: (dy/dt) = v (dv/dt) = y - y^3 + c(sin t) where c is a constant. I've been using the "deriv()" function and it seems to work out the best, but I'm having trouble converting the above formula to R code. Thank you, Tim Sharac Sign up for Internet Service under $10

Hello, I am having troubles with heat conduction problem. Below is the given information. Should I move forward with this problem like any other 1-D PDE? ?T/?t = a* (?^2T/?x^2) I.C. For t = 0 and 0 ? x ? 10, T = 0 ?C B.C. For x = 0 cm and all t , T = 100?C For x = 10 cm and all t , T = 0 ?C The thermal diffusivity is a = 2.0 cm^2 /s. I also added what I have for code in R. Any help will

Hi, I am using package deSolve to run some ordinary differential equations (ODE) as part of a mathematical modeling project. I have solved for the following equilibrium states: Seq1<-a*(1-Neq1)/(f*Veq1+m+d) Ceq1<-(f*Seq1*Veq1+g*Ieq1+r*(1-Neq1)-b1*Veq1*Ieq1)/(b2+m+d+g) Ieq1<-(-b2*Ceq1)-r*(1-Neq1)/(b1*Veq1-g-u) Veq1<-o*(Ceq1+Ieq1)/e I want to take the differential of both sides of

Hi , I open secure Session with X11 forwarding. when run any standard X applicattion like xterm xclock it come up without any error. I start my user X application it fails. On User application side it fails when "xtOpenDisplay" system call with localhost:10.0. On SSH server debug message are : > debug1: X11 connection requested. > debug2: fd 20 setting TCP_NODELAY >

That works. Thanks. One more followup question though. Once i run opt on bitcode, there is not useful output/transform on bitcode. this rpt files are extra. I am hoping to do something like this, ; RUN: FileCheck --input-file=a.rpt.gold --check-prefix=CHECK-A < a.rpt ; RUN: FileCheck --input-file=b.rpt.gold --check-prefix=CHECK-B < b.rpt i did not find much examples in tests hence

Hi all, I have n no. of extensions in my dialer. from 456 to 556 extensions. I was created 2 other extensions 667 and 668 I need to allow only STD calls to go from this extensions. These all extensions are same context . I need to define the STD dialplan for only this 2 extensions. how I can ? Best Regards, Mahesh Katta *BUZZ**WORKS* Business Services Private Limited BANGALORE | CHENNAI |