R Blogs

December 17th, 2009

There are many blogs on Statistics, R and other related topics scattered around the internet. The R bloggers website provides a central hub where feeds from participating blogs are collated so that they can be viewed from a single website. Read the rest of this entry »

The Grammar of Graphics: ggplot2 package

December 14th, 2009

The grammar of graphics approach to constructing graphs has been implemented in the ggplot2 package in R. The author of the package, Hadley Wickham, has provided a website with many details of using the system to create nice looking graphics. Read the rest of this entry »

Summarising data using bar charts

December 12th, 2009

A bar graph is a frequently used type of display that compares counts, frequencies, totals or other summary measures for a series of categories, e.g. sales in different market sectors or in quarters in a financial year. The bar graph can be laid out with the categories either on the vertical or horizontal axis of the display – depending on whether we consider making a vertical or horizontal comparison is easier for interpreting the graph. Read the rest of this entry »

Design of Experiments – Blocking and Full Factorial Experimental Design Plans

December 6th, 2009

When considering using a full factorial experimental design there may be constraints on the number of experiments that can be run during a particular session, or there may be other practical constraints that introduce systematic differences into an experiment that can be handled during the design and analysis of the data collected during the experiment. Read the rest of this entry »

Design of Experiments – Full Factorial Designs

December 1st, 2009

In designs where there are multiple factors, all with a discrete group of level settings, the full enumeration of all combinations of factor levels is referred to as a full factorial design. As the number of factors increases, potentially along with the settings for the factors, the total number of experimental units increases rapidly. Read the rest of this entry »

Statistics Books