Last month I attended the CeBIT trade fair in Hannover. Besides the so called “shareconomy” there was also another main topic across all expedition halls - Big Data. This subject is not completely new and I think that a lot of you also have experiences with some of the tools associated with Big Data. But due to the great...
Today’s blog post is about a problem known by most of the people using cluster algorithms on datasets without given true labels (unsupervised learning). The challenge here is the “freedom of choice” over a broad range of different cluster algorithms and how to determine the right parameter values. The difficulty is the following: Every clustering algorithm and even...
On November, the 27th, a special post took my interest. Scott Mutchler presented a small framework for predictive analytics based on the PMML (Predictive Model Markup Language) and a Java-based REST-Interface. PMML is a XML based standard for the description and exchange of analytical models. The idea is that every piece of software which supports the corresponding...
Some time ago I stumbled upon a problem connected with the labels of a clustering. The partition an instance belongs to, is mostly labeled through an integer ranging from 1 to K, where k is the number of clusters. The task at that time was to plot a map of the results from the clustering of spatial polygons...
A typical step in a lot of data mining methods is the calculation of a distance between entities. For example using the nearest-neighbor method it is crucial to do this calculation very efficiently because it is the most time-consuming step of the procedure. Just imagine you want to compute the Euclidean distance between a constantly changing database...
Zero Inflated Models and Generalized Linear Mixed Models with R.
Zuur, Saveliev, Ieno (2012).
