LaTeX is very strong for typesetting mathematical equations. Read the rest of this entry »
LaTeX Typesetting – Basic Mathematics
August 1st, 2011Getting rid of white space at the beginning and end of a string
July 28th, 2011There are situations where we are working with character strings extracted from various sources and it can be annoying when there is white space at the beginning and/or end of the strings. This whitespace can cause problems when attemping to sort, subset or various other common operations. Read the rest of this entry »
R.NET
July 4th, 2011The R.NET project provides a mechanism for communicating with R from a .NET application. This appears to be a promising way to create simple interfaces to some of the functionality of R. Read the rest of this entry »
Generalized Linear Models – Poisson Regression
June 26th, 2011The Generalized Linear Model (GLM) allows us to model responses with distributions other than the Normal distribution, which is one of the assumptions underlying linear regression as used in many cases. When data is counts of events (or items) then a discrete distribution is more appropriate is usually more appropriate than approximating with a continuous distribution, especially as our counts should be bounded below at zero. Negative counts do not make sense. Read the rest of this entry »
Handling Errors Gracefully
May 27th, 2011In R functions sometimes produces warnings or errors. In the case of errors execution of a function or a series of commands can get halted when an error occurs, which can in some cases be frustrating especially if we want to continue our calculations. Read the rest of this entry »
Fractional Factorial Designs using FrF2
May 18th, 2011The FrF2 package for R can be used to create regular and non-regular Fractional Factorial 2-level designs. It is reasonably straightforward to use. Read the rest of this entry »
RStudio
April 29th, 2011R Matrix Operations
March 27th, 2011R can be used to perform various matrix calculations. This include functions for creating matrices (matrix), addition (+), multiplication (%*%) and inversion (solve). Read the rest of this entry »
R Package Automated Download
March 6th, 2011There are situations where we might want to run R on a standalone machine so need to download a (potentially) large number of packages to install on this system. Rather than having to through the pain of searching through CRAN to find the packages and all the dependencies and manually download, it would be nice to be able grab all available packages in one go and then set them up as a local repository. Read the rest of this entry »
Statistical Graphics – Edward Tufte
February 15th, 2011The work of Edward Tufte is worth reading if you are interested in designing meaningful graphs and removing chart junk from your displays. Read the rest of this entry »
