Posts tagged with multivariate data

Deriving biological meaning from principal components analysis

August 1st, 2007

Back from Madrid. I spent three weeks there on an excellent data analysis course, which I would recommend. Not only did I learn valuable techniques, I also got the chance to spend my evenings by the pool or in Sol eating tapas - which explains the lack of posts this July. I offer this brief tutorial in recompense, continuing the theme of data analysis.

Read more »

Visualising and exploring multivariate datasets using singular value decomposition and self organising maps

July 17th, 2007

Hola from Madrid, I’ve come here for a data analysis summer school. Last week, there was an interesting class on dimensionality reduction, and since multivariate datasets are prevalent in this -omic era, I thought to post a discussion of what I learnt. The aim of this example is illustrate one technique for visualising multivariate data, singular value decomposition, and a second technique for exploring it, self organising maps.

Read more »