Introduction One of the first stages in most data analysis projects is about exploring the data at hand. During this stage the analyst tries to get familiar with his dataset by looking at summary statistics, feature distributions and relationships be... [Read more...]

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Since I started using Tableau I’m quite fascinated about the capabilities of this piece of software. Before Christmas I was looking how I could build an interactive visualization that helps me to explore the relationships between different objects in a form that shows which objects are very close to ... [Read more...]

Last quarter was a bit too busy to write some new blog post because of a new job. And changing the job often come along with changing the tools you work with. That was my way to Tableau. Tableau is one of the new stars in the BI/Analytics world ... [Read more...]

Introduction and Background While my last posting was about recommendation in the context of Location Based Social Networks there are also other interesting topics regarding the analysis of unstructured data. The most established one is probably Text Analytics/Mining focusing on all sorts of text data.For me, coming from ... [Read more...]

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 ... [Read more...]

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 ... [Read more...]

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 ... [Read more...]

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 ... [Read more...]

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 ... [Read more...]