Even though most modern computers already have four cores that can be used to speed up analysis – see here for a description. However, after starting to do more simulation studies it became apparent that this is highly impractical. The solution: Running R via R-studio on Amazons cloud servers. Thanks to ... [Read more...]

Many students struggle to find an adequte format for their thesis. Ironically the advent of “modern” WYSIWYG programms seems to make it harder to consistently format a text. While learning LaTeX may be a bit too much to ask for, markdown is a very minimal language that together with pandoc ... [Read more...]

In my last post I showed how one can easily summarize the outcome of a logistic regression. Here I want to show how this really depends on the data-points that are used to estimate the model. Taking a cue from the evolution of a correlation I have plotted the estimated ... [Read more...]

Hi, if you like me work in medical research, you have to plot the results of multiple logistic regressions every once in a while. As I have not yet found a great solution to make these plots I have put together the following short skript. Do not expect too much, ... [Read more...]

I recently thought about ways to visualize medications and their co-occurences in a group of children. As long as you want to visualize up to  4 different medications you can simply use Venn diagrams. There is a very nice R-package to generate these kind of graphics for you (for a  description ... [Read more...]

In this post I way to share with you some code to use Openstreetmap – maps as a backdrop for a data visualization. We will use the RgoogleMaps-package for R. In the following I will show you how to make this graph. 1. Download the map I wanted to take a closer ... [Read more...]

This Article is also available in EN, ES. [Read more...]

After working more seriously with simulations I noticed some updates were necessary to my previous setup. Most notably are the following three: It is very handy to explicitly call the different scenarios instead of using nested loops Storing intermediate results in single files obliviates the need to rerun an almost ... [Read more...]

Based on a related post on one of my favorite python-lists I remembered, that I wrote a similar snipplet some time ago. So if you want to dump your whole MySQL database to csv-files you can recycle the following code: ?Download mysql2cvs.R1 2 3 4 5 6 7 8 9 require(RMySQL) m [Read more...]

The analysis of geospatial information is currently a big trend in medicine and public health. Even though some may want to convince you that this can only be achieved with the latest and most expensive software, I am not convinced. First, analysis  of spatial data dates back to at least 1856 ... [Read more...]

Sometimes when working with small paired data-sets it is nice to see/show all the data in a structured form. For example when looking at pre-post comparisons, connected dots are a natural way to visualize which data-points belong together. In R this can be easily be combined with boxplots expressing ... [Read more...]

RStudio is a graphical user interface for R. Or as the developers put it. RStudio™ is a new integrated development environment (IDE) for R. RStudio combines an intuitive user interface with powerful coding tools to help you get the most out of R.   While there have been a few projects (... [Read more...]

  This Article is also available in EN, ES. [Read more...]

So after yesterdays post you probably ran this fancy new confirmatory factor analysis (CFA) – showed your friends all the cool fit stats and… nothing. As important as doing things right is being able to let others know that. For CFA the method of choice to illustrate the connections between variables ... [Read more...]

Describing multivariate data is not easy. Especially, if you think that statisticians have not developed any new tools after the ANOVA and principal component analysis (PCA). For social and experimental scientists the most important new technique are structural equation models that combine measurement models (that substitute reliability analysis and PCA) ... [Read more...]