similar to: PDE

Dear all, I am a SAS user, who's trying R. I am a little bit lost for graphics. What is the simplest way for plotting y as a function of x with one symbol (line or dot) for each level of a class variable z (for SAS langage= plot x*y=z). Can I add vertical bars for standard deviation stored in a separate variable (say ystd). Finally, is it possible to do all this with xyplot function

Hi, I'm trying to make a regression of the form : formula <- y ~ Asym_inf + Asym_sup * ( (1 / (1 + (n1 * (exp( (tmid1-x) / scal1) )^(1/n1) ) ) ) - (1 / (1 + (n2 * (exp( (tmid2-x) / scal2) )^(1/n2) ) ) ) ) which is a sum of the generalized logistic model proposed by richards. with data such as these: x <- c(88,113,128,143,157,172,184,198,210,226,240,249,263,284,302,340) y <-

Hi, I have two series of data set (it's measurment of growth but under two different conditions). To model these data I use the same function which is : formula <- y ~ Asym_inf + Asym_sup * ( (1 / (1 + (n1 * (exp( (tmid1-x) / scal1) )^(1/n1) ) ) ) - (1 / (1 + (n2 * (exp( (tmid2-x) / scal2) )^(1/n2) ) ) ) ) After the estimation of the parameters thanks to "nls", I have 2

Is there a package in R which implements numerically solves pde ? Thanks, Tolga

Dear Group Members, Forgive me if I am a little bit out of subject. I am looking for a good way to test the homogeneity of two variance-covariance matrices using R, prior to a Hotelling T test. Youll probably tell me that it is better to use a robust version of T, but I have no precise idea of the statistical behaviour of my variables, because they are parameters from the harmonics of

Hi,I am trying to port the Matlab code in the link below to R: http://en.literateprograms.org/Asian_Option_Pricing_(MATLAB)This code solves a PDE with initial and boundary conditions.Could anyone point me in the right direction in terms of what packages I should use ?Best Regards,Tom [[alternative HTML version deleted]]

I am trying to restart on R after 2 months stop. Start with previously functioning procedure: "ch<-odbcConnect("dBase Files")" get "Warning message: ODBC connection failed in: odbcConnect("dBase Files") " I have tried unsuccessfully different working directories. The only change I see is that I am working with a new login account on the same machine.

A disturbing behaviour of R: an import of data using RODBC library (Windows 98, R 1.1.1) recognizes accented characters in variables names but these can't be manipulated further. See below: > library(Rodbc) > ch<-odbcConnect("Paradox Files") > pollut<-sqlFetch(ch,Pollutio) > pollut Mortalit? Densit? Pollution 1 82 600 110 2 97 960

Dear all, I need your advice since I am looking for an implementation of the parabolic cylinder function in R. I found implemantations of the hypergemetric functions (the Whittaker and the confluent hypogeometric functions) in the package fAsianOptions but the parabolic cylinder function was unfortunately not there. Do you know of such implementation? Thank you very much for your advice.

Hi everyone, Can anyone give me more details about the 'lp', 'risk', 'terms', and 'expected' options from the predict.coxph function? I actually found that risk is obtained from exp(lp). I can't find information on 'expected' type however. Is anybody can expand the information on this function? Thank you in advance, I will appreciate it.

Dear R users and experts, I want to fit a shifted parabolic function with the following functional form to my data: f(x)=a0*(x+a1)^2+a2 (a0, a1 and a2 are scaling factors.) What is standard approach to do this in R? I tried the "lm" function in R but I got problems getting the above functional form. Any help is welcome :) . Greetings, Henri

Some naive questions: 1) How to remove a column in a data frame? I expected that rm would work but this is not the case (e.g. rm(dat$yyy) gives Warning message: remove: variable dat$yyy was not found). I only found to assign NULL value (e.g.: dat$yyy<-NULL). Is it the right way? 2) Is the place formerly occupied by dat$yyy automatically gained by R for other uses? 3) If t1 and t2 are 2 only

I want to get subsets averaged on numeric variables number 5:13 but I get the error below that I cannot understand. > is.factor(dat$Statut) [1] TRUE > s<-ave(dat[,5:13],dat$Statut) Error in [<-.data.frame(*tmp*, , value = if (n) { : Argument "i" is missing, with no default Thanks in advance --------------- Charles RAUX, Laboratoire d'Economie des Transports

After searching in R- Introduction, FAQ, help... I don't understand this: I write a function in a file (.R): tt <- function(mc) { date() mc<-read.csv2("machines.txt",na.strings="") date() } I source it in R and I type tt(). The answer is > tt() [1] "Mon Aug 14 11:18:25 2000" > The instructions following the first "date()" are ignored. Why?

I use hierclust (hierarchical clustering) in multiv package. In the documentation it is said that plclust (plotting a dendrogram) is available in S-plus. Can I find it anywhere (I have searched through http://lib.stat.cmu.edu/S and found only quotations of plclust in multiv) or is it only part of the S package (which I don't have)? Thanks --------------- Charles RAUX, Laboratoire

3 general questions: 1) How can I have the plot History Recording automatically turned on each time I start R (Windows)? 2) How can I have some libraries automatically loaded at R start? 3) As far as I know weights can be specified only for lm. How can I take account of weights with a weighted sample in other models or functions (table but also other multivariate and cluster techniques)? Thanks

I''m trying to install weborb in my applications but it is not working as you can see: C:\RoR\mijnapplication>ruby script/plugin install http://themidnightcoders.net:8 089/svn/weborb --force to reinstall + ./README + ./Rakefile + ./init.rb + ./install.rb + ./lib/AC_OETags.js + ./lib/InfoService.rb + ./lib/data-management-config.xml + ./lib/example.html + ./lib/example.mxml +

Hello, I would like to transform a contingency table (A x B) into a data frame while keeping the cross-tabulation structure (i.e. rows = levels of A, columns = levels of B). I have tried as.data.frame, xtabs, etc... and always got a "flattened" list of 3 variables (A, B, Freq). How to do that? Thanks in advance Charles Raux

How can I draw a 3D perspective of a contingency table, that is showing 3D bars whose height is in proportion of the table cells? --------------- Charles RAUX, Laboratoire d'Economie des Transports CNRS-Universit? Lumi?re Lyon 2-ENTPE email : charles.raux at let.ish-lyon.cnrs.fr http://www.ish-lyon.cnrs.fr/let -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-

I used in previous versions of R (R 1.1) to plot axes on projections of factorial coordinates using the function plaxes. This doesn't exist any more. Why this change ? No alternative ? --------------- Charles RAUX, Laboratoire d'Economie des Transports CNRS-Universit? Lumi?re Lyon 2-ENTPE email : charles.raux at let.ish-lyon.cnrs.fr http://www.ish-lyon.cnrs.fr/let