World dynamics, as defined in the World2 model of Forrester (1971).

The first doomsday computer model, based on Forrester’s System Dynamics, revisited with the R programming language

“In 1972 a small paperbound book called ‘The Limits to Growth’ was published with much fanfare […] the book warned that the world was steering a course for disaster. Without a drastic change in direction, the human population would run out of food and natural resources, or else would choke on its own pollution, within 50 or 100 years” (Hayes, 1993).

Jay Wright Forrester (1918–2016) was an American computer engineer and systems scientist, credited as the “founding father” of system dynamics. Although less known by the general public than the Meadows couple who wrote ‘The Limits to Growth’ (Meadows et…

From K-means to Gaussian Mixture Modelling, condensed in a few lines of code

In the Machine Learning literature, K-means and Gaussian Mixture Models (GMM) are the first clustering / unsupervised models described [1–3], and as such, should be part of any data scientist’s toolbox. In R, one can use kmeans(), Mclust() or other similar functions, but to fully understand those algorithms, one needs to build them from scratch. An online search will guide you towards many useful tutorials but you will be hard-pressed to find fully transparent R codes. The best example I came upon is the excellent article ‘An Intro to Gaussian Mixture Modeling’ on R-bloggers.

But I still remained somewhat unsatisfied…

AM

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