# Blog Archives

## Illustrated Guide to ROC and AUC

June 23, 2015
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(In a past job interview I failed at explaining how to calculate and interprete ROC curves – so here goes my attempt to fill this knowledge gap.) Think of a regression model mapping a number of features onto a real number … Continue reading →

## Introduction to OpenCPU for R on EC2 with Python

February 15, 2015
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OpenCPU is (simply put) a server implementing a RESTful web API for remotely executing R functions and retrieving results. In this tutorial I am going to showcase how OpenCPU can be installed on an EC2 instance running Ubuntu 14.04. Python and … Continue reading →

January 19, 2015
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## Germans used to have more Sex in Summer!

January 1, 2015
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Wow – what a headline … okay, I admit it’s phrased quite sensational given that it anticipates just one possible interpretation of increasingly more births around summer / autumn compared to in spring … but I guess I just get … Continue reading →

## Hierarchical Clustering with R (feat. D3.js and Shiny)

December 14, 2014
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Agglomerative hierarchical clustering is a simple, intuitive and well-understood method for clustering data points. I used it with good results in a project to estimate the true geographical position of objects based on measured estimates. With this tutorial I would … Continue reading →

## Twitter’s REST API v1.1 with R (for Linux and Windows)

September 22, 2014
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In this tutorial I am going to describe a straightforward way of how to make use of Twitter’s REST API v1.1. For that purpose I composed a little package (RTwitterAPI), so that requesting data just needs the API URL, the API parameters … Continue reading →

## MongoDB – State of the R

August 31, 2014
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Naturally there are two reasons for why you need to access MongoDB from R: MongoDB is already used for whatever reason and you want to analyze the data stored therein You decide you want store your data in MongoDB instead of … Continue reading →

## Reasonable Inheritance of Cluster Identities in Repetitive Clustering

August 15, 2014
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… or Inferring Identity from Observations Let’s assume the following application: A conservation organisation starts a project to geographically catalogue the remaining representatives of an endangered plant species. For that purpose hikers are encouraged to communicate the location of the plant … Continue reading →

## Talking to Twitter’s REST API v1.1 with R

June 10, 2014
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In this text I am going to describe a very straightforward way of how to make use of Twitter’s REST API v1.1. I put some code together for that purpose, so that requesting data just needs the API URL, the API … Continue reading →

## FIR Filter Design and Digital Signal Processing in R

May 15, 2014
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This article serves the purpose of illustrating that signal processing with R is possible – thanks to the signal package – and to keep a reference of some of the stuff that I learned at my last edX course. Anyway, I … Continue reading →