A former WU-member, Michael Hahsler, created a really nice package called recommenderlab, which allows you to build collaborative filtering systems.

Wrangling data can be a real pain, especially if you work with unstructured or semi-structured data. I had to convert a JSON object into an dataframe in R, which should be easy using jsonlite, but it was not - So I used tidyjson and I really like it.

I was not able to install the R-package FSelector, because a dependency could not be installed properly.

I had to analyse a big dataset (>12GB). Although I have enough memory, it needs a lot of time so I looked for some optimisations - with success.

In R it's often mandatory to use formulas. Here I will explain the basic syntax and give some tips how to write shorter formulas.