The R software system is primarily command line based so when there are large sets of data it is not easy to browse the data frames. There are various useful functions for working with data frames. For example, after loading data from a text file we might want to view ... [Read more...]

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The Balanced Incomplete Block Design (BIBD) is a well studied experimental design that has various desirable features from a statistical perspective. The crossdes package in R provides a way to generate a block design for some given parameters and test wheter this design satisfies the BIBD conditions. For a BIBD ... [Read more...]

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The LaTeX beamer package can be used to create appealing presentations for many applications. A working knowledge of LaTeX is required but once the initial learning curve and transition is made from a visual word processor to a markup based approach the benefits are worth the initial investment of time. ... [Read more...]

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. Fast Tube by Casper The “Statistics” menu provides access to some analysis of variance models ... [Read more...]

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. Fast Tube by Casper The “Statistics” menu provides access to some analysis of variance models ... [Read more...]

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. Fast Tube by Casper ... [Read more...]

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. Fast Tube by Casper The “Statistics” menu provides access to various statistical models via the “Fit models” sub-menu ... [Read more...]

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. Fast Tube by Casper The “Statistics” menu provides access to various hypothesis ... [Read more...]

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. Fast Tube by Casper The R Commander GUI has two menus “Data” and “Statistics” that ... [Read more...]

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 ... [Read more...]

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When we have a set of data with a small number of variables we can easily use a manual approach to identifying a good set of variables and the form they take in our statistical model. In other situations we may have a large number of potentially important variables and ... [Read more...]

There are situations in regression modelling where robust methods could be considered to handle unusual observations that do not follow the general trend of the data set. There are various packages in R that provide robust statistical methods which are summarised on the CRAN Robust Task View. As an example ... [Read more...]

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