similar to: Getting subsets of a data frame

I tried to assign values to specific elements of a time series and got in trouble. The code below should be almost self-explanatory. I wanted to assign 0 to the first element of x, but instead I assigned zero to the second element of x, which is not what I wanted. Is there a function that will allow me to do this without going into index arithmetic (which would be prone to errors)? FS >

This is probably a dumb question, but I cannot figure it out. Why does this happen? dt <- as.Date("1954-02-01") > as.character(dt) [1] "1954-02-01" > sapply(c(dt), as.character) [1] "-5813" Thanks. FS

I am trying to find a way to assign values to elements of a vector that will be defined by a user. So I don't have the name of the vector and cannot hard code the assignment in advance. In the example below I have to get() the vector using its name. When I try to assign to an element I get an error: > a <- c(1,2,3) > get('a')[1] <- 0 Error: Target of assignment expands to

I noticed that when one tries to extend a time series (ts) object by a single period using window() actually two observations (NAs) are added. See below for an example. Does anyone know the reason for this behavior and how to avoid it? Thanks. FS > x<-ts(c(1,2,3)) > x1<- window(x, start(x), end(x) + 1, extend = TRUE) > x1 Time Series: Start = 1 End = 5 Frequency = 1 [1] 1 2

I declared the environment of the function myfun to be NULL as follows: environment(myfun) <- NULL Later on I called that myfun and got an error message because the function index() in the zoo package was called inside myfun and was not visible: Error in myfun(args) : couldn't find function "index" I tried to use zoo::index() instead of index(), but that did not work. In fact,

I discovered a bug in a program I am writing which was due to the program using a global variable within a function. For example, myfunc <- function(x) { y} That is, I made a mistake when defining the function and wrote "y" when I should have written "x". However, there was a variable y in the global environment and the function "worked" but gave the wrong

When doing polynomial regression I believe it is a good idea to use the poly function to generate orthogonal polynomials. When doing this in Splus there is a handy function (transform.poly I think) to convert the coefficients produced by regression with the poly function back to the original scale. Has somebody written something similar for R ? Robert

Hi! I had a database with some variables in sequence. Let me say: TX01, TX02, TX03 and TX04. But I need to run some regressions changing the variables... so: variable <- paste("TX0", 1:4, sep="") for(i in 1:4){ test[i] <- lm(variable[i] ~ INCOME, data=database) } But doesn't work... lm tries to find a variable inside database named variable[i] ... Suggestions?

One thing that has given me trouble is the fact that the time series implementation in the class ts relies on the concept of a "start" to the time series. For example, if I have ts1 <- ts(c(1,2,3)) dts1 <- diff(ts1) then dts1 will be a vector c(1,1) but with the attribute start = 2. Similarly, when one takes lags the "start" is moved around and the underlying vector

I wanted to create a list with the names of variables and their values. So I wrote the following function. add.to.list.names.vars.1 <- function(lnv, vnv) { i <- 1 while (i < length(vnv)) { z <- as.character(eval(substitute(quote(vnv[i+1])))[[2]][[i + 2]]) lnv[[vnv[i]]] <- list(Name = z, Value = vnv[i+1]) i <- i + 2 } lnv } It works, but it is very

I thought system.time() would return three numbers, the first two adding up to the third one. However, this does not hold in my system running Windows Vista Home Premium, with an Intel Core 2 Duo processor. For example, using the code in the help for system.time() (with one zero added), I got: > system.time(for(i in 1:100) mad(runif(10000))) user system elapsed 0.27 0.00 0.25 Is

It seems that my Rprofile.site file is not executed when I start R. To test this I included the following code in that file: .First <- function(){ cat("\nWelcome at", date(), "\n") flush.console() } When I start R the message above is not displayed. I am running R 2.6.1 (rgui.exe) under Vista Home Premium. The Rprofile.site is in the etc folder and the R_PROFILE

Is there a way to have an R program send an email? Something like this: address <- 'abc at d.com' text <- 'This is the email body' send.email(address, text) Thanks. FS

Can someone shed some light on this obscure portion of the help for lm? "Considerable care is needed when using 'lm' with time series. Unless 'na.action = NULL', the time series attributes are stripped from the variables before the regression is done. (This is necessary as omitting 'NA's would invalidate the time series attributes, and if

hi im a bioinformatics student as i have never had any previous programming experience i need help this is the question i need to answer: Random walk model we want to model a random walk where you take a step to the left with probability p and one to the right with probability 1-p. Now assume that there is a line of 11 squares. once you are in square 0 or in square 10 the walk ends. The aim

I am having a problem with optim() using the "L-BFGS-B" method. When I set the lower limit for the third parameter equal to zero I get an error message: > low.lim.3 <- 0 > phi_opt <- optim(phi_, model_lik, NULL, method = "L-BFGS-B", lower=c(0.2, -100, low.lim.3, 0), upper= c(10, 100, 10, 10), control = list(maxit = 1000, parscale = c(0.2, u1, 0.002, 0.002), trace =

Dear WizaRds! A trivial question indeed on selecting subsets in data frames. I am sorry. Unfortunately, I did not find any helpful information on the introduction, searched the help archive and read in introductory books. Please help: I want to select column "KB" which is read via read.csv2 as a data.frame into d. I checked that it is indeed a data.frame object and included the

Hi! Is there a Gui for R with improvements in the command line? I'm not looking for buttons, menus and etc, but (more) colored syntax, auto-complete commands and etc? Best regards, Raphael Saldanha saldanha.plangeo@gmail.com [[alternative HTML version deleted]]

Hi! Is there some R version for flashdisk, pendrive etc ? -- Regards, Raphael Saldanha saldanha.plangeo@gmail.com [[alternative HTML version deleted]]

Hi! I have to import some TXT files into R, but the separation between the columns are made with different blank spaces, but each file use the same separation. Example: 31 104 5 0 11RUA SAO SEBASTIAO 25 BAIRRO FILETO 01