similar to: Fast String operations in R ? Cost of String operations

What is the fastest way to compare two strings in R? Ralf

Is it possible to remove all variables in the current environment through a R command. Here is what I want: x <- 5 y < 10:20 reset() print(x) print(y) Output should be NULL for x and y, and not 5 and 10:20. Can one do that in R? Best, Ralf

Hi fans, is it possible for a script to check if a library has been installed? I want to automatically install it if it is missing to avoid scripts to crash when running on a new machine... Ralf

Are there packages that allow improved String and URL processing? E.g. extract parts of a URLs such as sub-domains, top-level domain, protocols (e.g. https, http, ftp), file type based on endings, check if a URL is valid or not, etc... I am currently only using split and paste. Are there better and more efficient ways to handle strings e.g. finding sub-strings or to do pattern matching? What

Can one create a variable through a function by name createVariable <- function(name) { outputVariable = name name <- NULL } after calling createVariable("myVar") I would like to have a variable myVar initialized with NULL in my environment. Is this possible? Ralf

Hi R-fans, I would like put out a question to all R users on this list and hope it will create some feedback and discussion. 1) What are your 3 most useful R package? and 2) What R package do you still miss and why do you think it would make a useful addition? Pulling answers together for these questions will serve as a guide for new users and help people who just want to get a hint where to

Hi R Users, I need to produce a simple report consisting of some graphs and a statistic. Here simplification of it: # graphics output test a <- c(1,3,2,1,4) b <- c(2,1,1,1,2) c <- c(4,7,2,4,5) d <- rnorm(500) e <- rnorm(600) op <- par(mfrow=c(3,2)) pie(a) pie(b) pie(c) text(ks.test(d,e)) obviously, the ks.test does not make it to the output. How can this be archived by a)

How can I create intersections of vectors? a <- c(1,2,3) b <- c(1,5,6) the intersected list c should contain c(1)... Ralf

Hi, in order to save space for a publication, it would be nice to have a combined scatter and density plot similar to what is shows on http://addictedtor.free.fr/graphiques/RGraphGallery.php?graph=78 I wonder if anybody perhaps has already developed code for this and is willing to share. This is the reproducible code for the histogram version obtained from the site: def.par <-

I am looking for a mailing list for general statistical questions that are not R related. Do you have any suggestions for lists that are busy and helpful and/or lists that you use and recommend? Thanks in advance, Ralf

Dear R users, I would like to great a frequency table from raw data and then access the classes/bins and their respective frequencies separately. Here the code to create the frequency tables: x1 <- c(1,5,1,1,2,2,3,4,5,3,2,3,6,4,3,8) t1 <- table(x1) print(t1[1]) Its easy to plot this, but how do I actually access the frequencies alone and the bins alone? Basically I am looking to get:

> Message: 21 > Date: Mon, 5 Jul 2010 02:26:29 -0400 > From: Ralf B <ralf.bierig at gmail.com> > To: "r-help at r-project.org" <r-help at r-project.org> > Subject: [R] Profiler for R ? > > Hi, > > is there such a thing as a profiler for R that informs about a) how > much processing time is used by particular functions and commands and > b) how

Here the general (perhaps silly question) first: Is it possible for a script to find out if it was sourced by another script or run directly? Here a small example with two scripts: # script A print ("This is script A") # script B source("C:/scriptA.R") print ("This is script B") I would like to modify script A in a way so that it only outputs 'This is script

I am a beginner in R, so please don't step on me if this is too simple. I have two data sets datax and datay for which I created a qqplot qqplot(datax,datay) but now I want a line that indicates the perfect match so that I can see how much the plot diverts from the ideal. This ideal however is not normal, so I think qqnorm and qqline cannot be applied. Perhaps you can help? Ralf

Hi experts, I am trying to write a very flexible method that allows me to add a new column to an existing data frame. This is what I have so far: add.column <- function(df, new.col, name) { n.row <- dim(df)[1] length(new.col) <- n.row names(new.col) <- name return(cbind(df, new.col)) } df <- NULL df <- data.frame(a=c(1,2,3)) df # corect: added NA to new collumn df <-

I have a code junk that produces a figure. In my special case, however, data does not always exist. In cases where data exists, the code chunk is of course trival (case #1), however, what do I do for case # 2 where the data does not exist? I can obviously prevent the code from being executed by checking the existence of the object x, but on the Sweave level I have a static figure chunk. Here an

I have two data sets, each a vector of 1000 numbers, each vector representing a distribution (i.e. 1000 numbers each of which representing a frequency at one point on a scale between 1 and 1000). For similfication, here an short version with only 5 points. a <- c(8,10,8,12,4) b <- c(7,11,8,10,5) Leaving the obvious discussion about causality aside fro a moment, I would like to see how

R Friends, I have data from which I would like to learn a more general (smoothened) trend by applying data smoothing methods. Data points follow a positive stepwise function. | x x | xxxxxxxx xxxxxxxx | x x |xxxx xxx xxxx | xxxxxxxxxxxxxxxxx | |

Hi all, I am looking for a good book that covers Machine Learning as a whole and provides examples in R while not over focusing on the math (such as in 'Elements of Statistical Learning') but rather on descriptions and examples. I am relatively new to R and ML and, while solving problems with R, I want to learn the main concepts, techniques and problem categories. Can anybody here

Hi, this following code: x<-c(1,2,NA) length(x) returns 3, correctly counting numbers as well as NA's. How can I exclude NA's from this count? Ralf