A duplicate finder based on cryptographic hash functions — Is this the same picture? Is there a copy of this file in the other folder? Recently I was going through some old files and and had to ask myself these questions quite often. I guess most of you have been in a situation like this. And as you may…

My grandmothers cook book meets machine learning part I — My grandmother was an outstanding cook. So when I recently came across her old cook book I tried to read through some of the recipes, hoping I could recreate some of the dishes I enjoyed as a kid. However this turned out harder than expected since the book was printed…

The world around is a dynamic mixture of signals from various sources. Just like the colors in the above picture blend into one another, giving rise to new shades and tones, everything we perceive is a fusion of simpler components. Most of the time we are not even aware that…

Downloading minute resolution OHLC data via exchange APIs — UPDATE: Because of the general interest in this matter I created a dataset including all OHLC data from the Bitfinex exchange API and uploaded it as a public dataset on Kaggle. Introduction Algorithmic trading is a popular way to tackle the fast-paced and volatile environment of cryptocurrency markets. However implementing an automated…

A biologically inspired linear classifier in Python — It has been a long standing task to create machines that can act and reason in a similar fashion as humans do. And while there has been lots of progress in artificial intelligence (AI) and machine learning in recent years some of the groundwork has already been laid out more…

Spike sorting — Epilepsy is a form of brain disorder in which an excess of synchronous electrical brain activity leads to seizures which can range from having no outward symptom at all to jerking movements (tonic-clonic seizure) and loss of awareness (absence seizure). For some epilepsy patients surgical removal of the effected brain…

Biological neural networks such as the human brain consist of specialized cells called neurons. There are various types of neurons but all of them are based on the same concept. Signaling molecules called neurotransmitters are released at the synapse, the connection point between two neurons. Neurotransmitters alter the membrane potential…

In the first article of this series we looked at the general organisation of MRI and fMRI datasets. In the second article we moved on and investigated which parts of the brain were active during the fMRI scan by performing a correlation analysis between the data and an idealized response…

In the previous article we covered the basics about the data structure and the differences between structural and functional MRI (fMRI). In this article we move on to the analysis of the fMRI data to answer the following question: What brain regions were active during the scan? This is actually…