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Data frames are lists Most R users will know that data frames are lists. You can easily verify that a data frame is a list by typing However, data frames are lists with some special properties. For example, all entries in the list must have the same length (here 2), etc. ... [Read more...]

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Today I stumbled across a figure in an explanation on multiple factor analysis which contained pictograms.   Figure 1 from Abdi & Valentin (2007), p. 8. I wanted to reproduce a similar figure in R using pictograms and additionally color them e.g. by group membership . I have almost no knowledge about image processing, so […] [Read more...]

After some time of using shiny I got to the point where I needed to send some arbitrary data from the client to the server, process it with R and return some other data to the client. As a client/server programming newbie this was a challenge for me as ... [Read more...]

I recently wanted to construe a dashboard widget that contains some text and other elements using the grid graphics system. The size available for the widget will vary. When the sizes for the elements of the grobs in the widget are specified as Normalised Parent Coordinates the size adjustments happen ... [Read more...]

In this post we collect several R one- or few-liners that we consider useful. As our minds tend to forget these little fragments we jot them down here so we will find them again. Indexing in nested loops Every once in a while I run a nested loop like the ... [Read more...]

Guest post by Daniel Adler. Below is a real-time audio-visual multimedia demonstration – or in short ‘an intro’ – written in 100% pure R. It requires no compilation and runs across major platforms via the package rdyncall and preinstalled precompiled standard libraries such as OpenGL and SDL libraries. This ‘happy-birthday’ production runs about 3 ... [Read more...]

The first week of April I attended an excellent workshop on biplots held by Michael Greenacre and Oleg Nenadić at the Gesis Institute in Cologne, Germany. Throughout his presentations, Michael used animations to visualize the concepts he was explaining. He also included  animations in some of his papers. This inspired ... [Read more...]

Yesterday I surfed the web looking for 3D wireframe examples to explain linear models in class. I stumbled across this site where animated 3D wireframe plots are outputted by SAS.  Below I did something similar in R. This post shows the few steps of how to create an animated .gif ... [Read more...]

In a previous post I gave some examples of how to make a progress bar in R. In the examples the bars were created within loops. Very often though I have situations where I would like have a progress bar when using apply(). The plyr package provides several apply-like functions ... [Read more...]

Lately, David Smith from REvolution Computing set out to challenge the R community with the reprocuction of a beautiful choropleth map (= multiple regions map/thematic map) on US unemployment rates he had seen on the Flowing Data blog. Here you can find the impressing results. Being a fan of beautiful ... [Read more...]

Most people using LaTex feel that creating tables is no fun. Some days ago I stumbled across a neat function written by Paul Johnson that produces LaTex code as well as LaTex code that can be used within Lyx. The output can be used for regression models and looks like ... [Read more...]

Just a little note for german speaking R beginners: There is an introductory course in R (german) available online on the website of the department of methodology and evaluation research at the University of Jena. Dr. Ivailo Partchev holds a seven sess... [Read more...]

Before you read this post, please have a look at Enrique’s comment below. He pointed out that the built-in R function modifyList() already does what I wanted to describe in this post. Well, I live to learn :) I was wondering how I could write a function that uses default ... [Read more...]

On the REvolutions Blog there is a nice posting treating the often raised concern on “How good or reliable R is”. At my university R is hardly used. Sometimes I was asked by lecturers wether the calculations done by R and its packages are accurate. The linked posting treats this ... [Read more...]

Sometimes I find it useful to merge two data frames like the following ones   X1 X2 X3 X4 Y1 Y2 Y3 Y4 1  o  o  o  o X X X X 2  o  o  o  o X X X X 3  o  o  o  o X X X X by using zip feeding ... [Read more...]

Every once in while I have to write a function that contains a loop doing thousands or millions of calculations. To make sure that the function does not get stuck in an endless loop or just to fulfill the human need of control it is useful to monitor the progress. ... [Read more...]

In some statistical programs there is the option available to attach a footnote to the graphical output that is created. This footnote may contain the name of the script or the file that produced the graphic, the author’s name and the date of creation. In SAS for example there ... [Read more...]