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...]

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...]

Although the graphic at the left might not seem a 100% appropriate, it gives a hint to what I am about to do. I want to calculate all possible linear regression models with one dependent and several independent variables. I do not want to address bias and fitting issues or the ... [Read more...]

Today I will treat a problem I encounter every once in a while. Let’s suppose we have several dataframes or vectors of unequel length but with partly matching column names,  just like the following ones: df1 [Read more...]