similar to: differential equations

Hi, I got a code from S that uses 'nlminb' to minimize a function with constraints. Is there a similar function in R? Thanks. R. Heberto Ghezzo Ph.D. Meakins-Christie Labs McGill University Montreal - Canada heberto at meakins.lan.mcgill.ca -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read

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 each polygon ID. At each time step, the parameter values

Hello, I wrote the following function to compute multiple comparisons in a one way anova and randomized blocks anova. aov1 <- function(y,g,s=NULL,comp="mca",meth="Sidak") { # fun <- function(x) c(mean(x,na.rm=T),sd(x,na.rm=T),length(x[!is.na(x)])) # li <- length(unique(g)) cat(" Analysis of Variance with Multiple comparisons\n\n") cat("

Hello everybody I am trying to extract some observations from a data frame, ie the subjects that belong to a given group, and although t-test etc work if I try to obtain the number of subjects in the subgroup i get some funny numbers. All the subjects with NA for group are included in the subgroups 'group==1' etc. Is this a bug? for example in Windoze R : Copyright 2001, The R

I am using R 2.0.2 on a WinXP I am trying to get the code of the Kruskal-Wallis test but > kruskal.test function (x, ...) UseMethod("kruskal.test") <environment: namespace:stats> > ls(3) [1] "acf" "acf2AR" "add.scope" .............. [181] "kruskal.test" "ks.test"

Hello, I think this qualify as a bug > x<-c(1,2,3,4,NA,6,7) > mean(x) [1] NA > mean(x,na.rm=T) [1] 3.833333 > sd(x) Error in var(as.vector(x)) : missing observations in cov/cor > sd(x,na.rm=T) Error in sd(x, na.rm = T) : unused argument(s) (na.rm ...) > var(x) Error in var(x) : missing observations in cov/cor > var(x,na.rm=T) [1] 5.366667 > why sd() does not

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)

Hello, I have a problem. I have to read a HUGE file which has to be line processed, so I would like to use scan like p <- scan(pfile,what=c(0,0,0,"",0,""),nlines=1) but it continues to read the first line, so I have to add a skip and increment the skip after each read. It takes forever to read a test file of 1 Mb, the real one is in 60's Mb Is there a way to read line

I've got a PhD student starting this year. She'll be working on data mining. She has asked for a reading list while she's still in her home country, which is a really good sign. Her cosupervisor and I don't (think we) have any problem with choosing things that are specifically about data mining, but there are some statistical ideas (sampling, exploratory-vs-confirmatory,

Hi I am using R65.1 in Windows 95 I have a CSV file from Excell > a<-read.table("c:/heberto/mgc/tst.csv",header=T,sep=",") > attach(a) > a manolo fvcpp fevpp fvvcpp tlcpp rvpp rvtlpp plmaxpp 1 1 99.28 97.67 98.38 91.14 102.9 111.25 117.64 2 1 86.97 68.56 78.89 94.60 112.34 118.53 159.20 3 1 81.12 71.76 88.37 89.16

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

Hi R friends, I havent asked a silly question in a long time so here it is: Reading the last issue of Stat Can J. there is an article in a single degree of freedom test for non aditivity of interactions in anova tables with 1 obs per cell. The authors claim it is more powerfull than Tukey but for the case of multiplicative interaction, which is the alternative studied by Tukey. I tried to

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

I would like to obtain a crosstabulation of means(var, quantiles...) i.e. I have a data frame with Var-i, Var-j, Var-k, Var-X, var-Y I like to have the mean of Var-X for each combination of Var-i,Var-j. One solution would be: by(var-i,Var-j,mean(Var-x)) but I would like it better formatted and with mean,S.Dev,n for each cell? Does anybody have some function to do this or some ideas how to go

Hi, I am relatively new to R programming. I have Guido's version on a Win95 Pentium with 32 Mb RAM. I tried to compile the Package MIXREG of Rolf Turner in S to R almost everything works OK but he has a function po = partial outer product as follows: po <- function(a,b) { array(apply(b,2,"*",a),dim=c(dim(a),dim(b)[2]))) } in S-Plus given x = ( 1 1 1 2 1 3 1 4

I received several answer to my querry re reading zipped files, R.Gentleman, Liaw Andy, BD Ripley,J Holtman, A.Matt, and others, sorry if I missed your names. a- use pipe to run external unzip to a file and read from there b- use gzfile() to open directly a gzipped file c- use zip.file.extract() solution b works like a charm, unfortunately it open gzipped files and not zipped files, would it be

Windows binaries at CRAN (bin/windows/Windows-NT/base) have been updated to R-1.1.0. See below for a list of Windows-specific changes. We thanks all the people who checked over pre-test versions. guido masarotto (for the R-core team) Windows-specific changes to R ============================= There is now a GUI preferences editor on the Edit menu in Rgui. A data entry editor is now

Windows binaries at CRAN (bin/windows/Windows-NT/base) have been updated to R-1.1.0. See below for a list of Windows-specific changes. We thanks all the people who checked over pre-test versions. guido masarotto (for the R-core team) Windows-specific changes to R ============================= There is now a GUI preferences editor on the Edit menu in Rgui. A data entry editor is now

Hello, Using R 1051 in win98 When I try to build a library Addreg with DESCRIPTION, Index and Title in R and subdirectories Man and R. From a Command window I do: c:\> c:\rw1051\bin\Rcmd INSTALL c:\r_src\src\library\addreg --library=c:\r\src\library make: Entering directory '/cygdrive/c/rw1051/src/gnuwin32' make DLLNM= \ -C c:/r_src/src/library/addreg PKG=addreg RHOME=c:/rw1051

Is there any R code available for solving ODE's? I am considering building an interface to ODEPACK, but don't want to duplicate any existing effort. -- Tom Wainwright NOAA/NMFS/NWFSC 2030 S Marine Science Dr Newport, OR 97365 USA thomas.wainwright at noaa.gov -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read