The following simple code can be used to find roots of functions (based on the secant algorithm), secant=function(fun, x0, x1, tolerence=1e-07, niter=500){for ( i in 1:niter ) { x2 <- x1-fun(x1)*(x1-x0)/(fun(x1)-fun(x0)) if (abs(fun(x2)) < to...

I'll be hosting a webinar tomorrow (Wednesday) aimed at R users who want to know more about how Revolution R Enterprise extends open source R for big data, Web services, multi-core processing, debugging and more. For R users at schools and universities, I'll also explain how you can download and use Revolution R Enterprise free of charge. The full...

I'll be hosting a webinar tomorrow (Wednesday) aimed at R users who want to know more about how Revolution R Enterprise extends open source R for big data, Web services, multi-core processing, debugging and more. For R users at schools and universities, I'll also explain how you can download and use Revolution R Enterprise free of charge. The full...

R evangelist David Smith, marketing VP at Revolution R, will be giving a webinar showing off some of the finer features of Revolution R Enterprise - an integrated development environment (IDE) for R that has an enhanced script editor with syntax highli...

Here is a quick-and-dirty solution to Le Monde puzzle posted a few days ago: the R code counts the number of winning tickets between 1 and N, and stops when there is a proportion of 10% of winning tickets. #winning ticket win=function(n){ #decimal digits decomposition x=rep(0,4) x=n%%10 m=(n-x)/10 x=m%%10 m=(m-x)/10 x=m%%10 m=(m-x)/10 x=m%%10 tic=0 for

I pushed highlight 0.2-5 on CRAN. This release improves the latex renderer and the sweave driver so that multiple lines character strings are properly rendered. This example vignette shows it: \documentclass{report} \begin{document} <<echo=FALSE,results=hide>>= old.op <- options( prompt = " ", continue = " " ) @ <<>>= require( inline ) require( Rcpp ) convolve <- cxxfunction( signature( a = "numeric", b...

The next update to R will be a patch release: R 2.12.1 will be released on December 16, as announced today by the R Core Team. As is typical for a patch release, this version will include some minor bug fixes plus a few new features (from the current build's NEWS file): The DVI/PDF reference manual now includes the...

The next update to R will be a patch release: R 2.12.1 will be released on December 16, as announced today by the R Core Team. As is typical for a patch release, this version will include some minor bug fixes plus a few new features (from the current build's NEWS file): The DVI/PDF reference manual now includes the...

Jeromy Anglim, fellow social scientist and R aficionado from across the globe, gave a great talk to the Melbourne R Users Group last week on the joys of creating reproducible results. A subject near and dear to me, but not one that is given enough attention in research training. Jeromy discusses tools for generating reproducible

Geoff Robinson discusses how to write simple and reusable R code. He provides several examples with code.

Jeromy Anglim discusses best practices and tools used to support reproducible research in R. He discusses tools for R scripting and version control; and provides examples of SWeave. This presentation was given to the Melbourne R Users Group (MelbURN)...

I was recently reading a bit about logistic regression in a book on hierarchical/multilevel modeling when I first learned about the "divide by 4 rule" for quickly interpreting coefficients in a logistic regression model in terms of the predicted probabilities of the outcome. The idea is pretty simple. The logistic curve (predicted probabilities) is steepest at the center where...

To be reductive, visual displays of quantitative information might be reasonably categorized on a continuum between “data display” and “statistical graphics.” By statistical graphics, I mean a plot that displays some summary of or relationship amongst several variables, likely having undergone some processing or analysis. This may be as simple as a scatterplot of a … Continue reading →

When were there bear and bull markets in US stocks since 1950? Smoothing While we’d really like to estimate the expected return at each point in time, finding bear markets is ambitious enough. The plan starts by smoothing the daily returns through time, as in Figure 1. Figure 1: Smoothed returns with a 4 year … Continue reading...

I will be running a workshop on Statistical Forecasting: Principles and Practice in Switzerland, 20-22 June 2011. Check out the venue: Waldhotel Doldenhorn, Kandersteg! So if you fancy a trip to the beautiful Swiss Alps next June, read on… Outline Forecasting is required in many situations: deciding whether to build another power generation plant in

A while back I outlined the setup process for running R under the Eclipse integrated development environment with the help of WalWare.de’s StatET plugin for Eclipse, in Windows 7. This post is an update on that procedure for the newer versions of...

In the continuation of my earlier post on computing evidence, I read a very interesting paper by Merlise Clyde, Joyee Ghosh and Michael Littman, to appear in JCGS. It is called Bayesian adaptive sampling for variable selection and model averaging. The sound idea at the basis of the paper is that, when one is doing

A Pareto plot is an enhanced bar chart. It comes in useful for deciding which bars in your bar chart are important. To see this, take a look at some made up DVD sales data. set.seed(1234) dvd_names <- c("Toy Tales 3", "The Dusk Saga: Black Out", "Urban Coitus 2", "Dragon Training for Dummies", "Germination", "Fe

That is the second tutorial of Rapidminer and R extension for Trading and the first in Video. In the last example the ROC obtained is not as good as it should be to make money in this business, To improve the strategy we will try to optimize the trading strategy. Different methods of optimization and objective functions...

I am doing a simple comparison of different estimation procedures in dealing with a simple binomial model. Here is where I got started:---------------------------------------------library(INLA)library(npmlreg)library(MCMCglmm)library(DPpackage)data(See...