A blog of Python-related topics and code.
Converting a spectrum to a colour
Posted by: christian on 27 Mar 2016
This article presents a Python script to map a spectrum of wavelengths to a representation of a colour. There is no unique way to do this, but the formulation used here is based on the CIE colour matching functions, $\bar{x}(\lambda)$, $\bar{y}(\lambda)$ and $\bar{z}(\lambda)$. These model the chromatic response of a "standard observer" by mapping a power spectrum of wavelengths, $P(\lambda)$, to a set of tristimulus values, $X$, $Y$ and $Z$, analogous to the actual response of the three types of cone cell in the human eye.
Hidden images in spectrograms
Posted by: christian on 19 Mar 2016
It is well-known that Aphex Twin incorporated images in the spectrogram of the final few seconds of a couple of tracks from the Windowlicker EP.
Do consecutive primes avoid sharing the same last digit?
Posted by: christian on 16 Mar 2016
An article by Oliver and Soundararajan that has got a lot of attention in the last few days notes that there is a curious pattern in the distribution of the final digits of consecutive prime numbers. Prime numbers larger than 5 must end in 1, 3, 7 or 9 (else they would be divisible by either 2 or 5), and it seems that a prime ending in any of these is less likely to be followed by another prime ending in the same digit.
Computer generated contemporary art
Posted by: christian on 5 Feb 2016
Just a quick selection of images randomly-generated by the following 10 lines or so of Python.
Cloud images using the diamond-square algorithm
Posted by: christian on 3 Feb 2016
The diamond-square algorithm is a popular method for generating images which resemble terrain, clouds or plasma. Its description on Wikipedia is as good as any and will not be repeated here.