similar to: if else statements in R

Hi there I thought this would be of particular interest to people using 'optim' functions and perhaps people involved with R development. I've been beaten down by R trying to get it to perform an optimization on a mass-balance model. I've written the same program in excel, and using the 'solver' function, it comes up with an answer for my variables (p, ACT, which

Hi, there I am a graduate student new to coding in S who is hitting a bit of a wall at present using an "optim" function. I am running into some troubles, and was hoping someone might be able to recognize where I am going wrong. As background: I have constructed a loop that carries out a 365-day calculation for a mass-balance model. Basically, the model depends on 2 variables (p,

Hi there, I've hit a bump in writing postscript files with special characters in the WinAnsi encoding on a windows machine. Here's some sample code: ########################################### postscript(file = "test.eps", encoding="WinAnsi.enc", width = 3, height = 5.5, onefile = TRUE, horizontal=FALSE, family = "sans", title =

Hi there, I just wanted to take a quick second to thank everyone who maintains this service- just in case you don't hear it enough, there are a plethora of people who rely on this service (as evidenced by the help archives), and even if they don't say it, are greatly thankful for what you do here. Not only are you providing a service to people who are learning R, but indeed helping

Hi there, I'm sure there's an easy answer to this, and I can't wait to see it. The question: is there an easy way to sort a data frame by it's row names? My dilemma: I've had to pull apart a data frame, run it through a loop to do some calculations and generate new variables, and then re-construct the chunks back into a data frame at the end. Doing this preserves the row

Hi, there I am trying to replicate an error message in subset() to see what it is that I'm doing wrong with the datasets I am trying to work with. Essentially, I am trying to pass a string vector to subset() in order to select a specific collection of cases (i.e., I have data for these cases in one table, and want to select data from another table that match up with the cases in the

Hi, My question is how do I gain control over what values the X and Y axis show. Below is a sample plot I have made and want the X axis to represent a time vector with values taking the form Q1.60, Q2.60, Q3.60...Q1.90..etc...Currently the X axis starts with value 0 and increases by 1 through the end of the sample. win.graph() matplot(v.0,log.diff.v.6,type="l",lty=1, col=2,

Hi, there I tried this post on R-help but did not generate any replies, so I thought I might try the waters here since it's a more programming-based group. I have written a function that will allow me to calculate the variance components for a model II (random effects) single factor ANOVA (perhaps this is me re-inventing the wheel, but I handn't yet come across anything in R that does

Hi, there I'm currently trying to figure out how to keep my "factor" levels for a variable when moving it from one data frame or matrix to another. Example below: vec1<-(rep("10",5)) vec2<-(rep("30",5)) vec3<-(rep("80",5)) vecs<-c(vec1, vec2, vec3) resp<-rnorm(2,15) dat<-as.data.frame(cbind(resp, vecs))

Hi there, Does anyone know how to extract elements from the table returned by Manova()? Using the univariate equivalent, Anova(), it's easy: a.an<-Anova(lm(y~x1*x2)) a.an$F This will return a vector of the F-values in order of the terms of the model. However, a similar application using Manova(): m.an<-Manova(lm(Y~x1~x2)) m.an$F Returns NULL. So does any attempt at calling the

Hi all, Does anyone have any tips for extracting chunks of data from a distance matrix? For instance, if one was interested in only a subset of distance comparisons (i.e., that of rows 4 thru 6, and no others), is there a simple way to pull that data out? >From some playing around with an example (below), I've been able to figure out that a distance matrix in R is stored as a single

Hi, all I have a rather un-ideal dataset that I am trying to work with, and would appreciate any advice you have on the matter. I have 4 years worth of data taken at 3 depth-zones from which samples have been taken at random. I am looking at the abundance of organism A between depth zones and across years, and am interested in the possible interaction of organism A distributions shifting

Hi there I am having trouble figuring out how to get an nlm function to report estimates for two parameter values in an estimation. The way I've got it goes something like this: f <- function (q, r) { here, I have a second loop which uses q, r to give me values for c, d below. a and b are already specified; this loop is a mass-balance function where I am trying to find values of q,

Hi, there I have a loop that is producing data, but is also generating an error message that I can't understand. Here's the loop and the error message: > bio<-matrix(NA, ncol=9, nrow=366) > W<-NULL > M<- length(Day) #number of days iterated > > for (i in 1:M) + { + + + if (Day[i]==1) W[i] <- Wo else W[i] <- (W[i-1]+(Gr[i]/Ef)) + + + C<-

Hi there, First off, thanks to everyone who has helped me so far. Sorry to keep pestering you all. I'm including my code here, and I will comment down it where it is that I am having problems figuring out how to write this damn thing. > temper <- scan("temp2.dat", na.strings = ".", list(Day=0, Temp=0)) Read 366 records > > Day <- temper$Day ;

I have a command that reads in some data: x <- read.csv("Sales2007.dat", header=TRUE) Then I try to organize the data: sc <- split(x, list(x$Category, x$SubCategory), drop=TRUE) Then I want to iterate through the data. I was able to get the following to run on the R console: for(i in 1:length(sc)) { sum(sc[[i]]$Quantity) } But notiing is primted on the console. I find

I feel greedy posting for help twice in one day- please forgive me, but the thesis can't wait. I have been trying to get an ?if else? statement working in a loop I am writing, in which I specify a variable value to 9.2 (Wo) on the first iteration, but for subsequent iterations, to adopt a value as a function of variables from the previous iteration. When I comment out the ?if else?

Dear R users, I have a txt file of the form 10092007 24.62 24.31 24.90 11092007 19.20 23.17 22.10 13092007 24.71 27.33 23.10 14092007 27.33 27.90 24.10 15092007 28.22 28.55 24.30 16092007 28.53 29.24 27.40 17092007 24.19 30.64 26.80 18092007 22.60 20.62 28.40 19092007 8.89 1.70 14.70 20092007 21.27 2.92 17.30 21092007 22.38 24.72 8.80 22092007 23.94 24.73 20.40 23092007 25.33 25.12 22.60

Dear List, I have examined the sp, maptools, and shapefiles packages (Windows) but cannot seem to figure out a solution for writing shapefiles for 'curvy shapes'. The scenario is that I generate a series of polygons, circles, and ellipses on a plot and would like to convert them to shapefiles. Since the circles and ellipses are do not return a coordinate list during the plotting

Dear List, Running on a PC (Windows 2000) with 256 MB RAM, Version R1.9.1 I have a relatively simple problem, which I can solve for relatively small datasets, but run into difficulties with larger ones. I believe that my approach is a hack rather than something elegant and I was hoping that somebody on this list might help me improve my code. Basically, given a vector of values (e.g.,