Classification Trees using the rpart function

September 21st, 2010

In a previous post on classification trees we considered using the tree package to fit a classification tree to data divided into known classes. In this post we will look at the alternative function rpart that is available within the base R distribution. Read the rest of this entry »

Classification Trees

September 18th, 2010

Decision trees are applied to situation where data is divided into groups rather than investigating a numerical response and its relationship to a set of descriptor variables. There are various implementations of classification trees in R and the some commonly used functions are rpart and tree. Read the rest of this entry »

Charting the performance of cricket all-rounders – IT Botham

August 16th, 2010

Cricket is a sport that generates a large volume of performance data and corresponding debate about the relative qualities of various players over their careers and in relation to their contemporaries. The cricinfo website has an extensive database of statistics for professional cricketers that can be searched to access the information in various formats. Read the rest of this entry »

R Commander – two-way analysis of variance

June 25th, 2010

Two way analysis of variance models can be fitted to data using the R Commander GUI. The general approach is similar to fitting the other types of model in R Commander described in previous posts. Read the rest of this entry »

R Commander – one-way analysis of variance

June 25th, 2010

One way analysis of variance models can be fitted to data using the R Commander GUI. The general approach is similar to fitting the other types of model in R Commander described in previous posts. Read the rest of this entry »

R Commander – logistic regression

June 23rd, 2010

We can use the R Commander GUI to fit logistic regression models with one or more explanatory variables. There are also facilities to plot data and consider model diagnostics. The same series of menus as for linear models are used to fit a logistic regression model. Read the rest of this entry »

R Commander – linear regression

June 18th, 2010

We can fit various linear regression models using the R Commander GUI which also provides various ways to consider the model diagnostics to determine whether we need to consider a different model. Read the rest of this entry »

R Commander – hypothesis testing

June 16th, 2010

The R Commander GUI can be used to perform classical hypothesis testing. There are menu options to undertake the variants on the t-test as well as tests on proportions or equality of variances for two samples of data. Read the rest of this entry »

R Commander – data manipulation and summaries

June 14th, 2010

Previously we considered the R Commander interface as a simple GUI for the R statistical software system. Here we will look at how to undertake data manipulation and creating basic statistical summaries of data sets. Read the rest of this entry »

R Commander – a good introductory GUI for R

June 1st, 2010

The R software is very powerful and flexible but one of the complaints of new users is that the learning curve is steep and can be daunting. There have been various projects to create GUIs for R with varying levels of sophistication, one of which is R Commander by John Fox. Read the rest of this entry »

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