Sigmoid NN

A Neural Network in Python, Part 2: activation functions, bias, SGD, etc.

9th February 2017

This is Part 2 of A Neural Network in Python, which was a very simple neural network to learn the XOR function. This part builds on that example to demonstrate more activation functions, learning a simple math function, adding a bias, improvements to the initial random weights, stochastic gradient descent, mean square error loss function, […]

Matrix Rain

Have we already seen this number? (deja vu again)

8th April 2016

I had a phone interview for a Python job the other day. It started out really well, he was very impressed with my CV and called me a ‘rocket scientist’. But then we got down to the technical questions and my brain decided to go out to lunch, and (yet again) I managed to snatch defeat […]

Python dictionary

A Python Dictionary

26th May 2015

This is simply a dictionary of Python keywords, implemented as – of course – a Python dictionary! Dictionaries are key:value pairs. The value can be any object, such as a tuple of strings. The first item in the tuple is part of the URL to documentation at, and the second item is a brief […]