On the Origin of Giraffe Matrices by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life

Today, during my talk on gene expression analysis at the kick-off meeting of the ERCIM Working Group on Computing & Statistics, I used the phrase giraffe matrix to refer to tall skinny matrices (with more rows than columns) and crocodile matrix for short fat matrices (with more columns than rows). A few hours later, Peter Rousseeuw adopted this terminology in his plenary talk on Algorithms for robust multivariate statistics. As I am writing, a search for these phrases on Google does not match any document.

I want to mention that I did not invent these phrases. I heard the terms matrice girafe, matrice crocodile, and matrice éléphant in 1998 in a course on matrix computations taught by Michel Munster at the University of Liège.

(Can you guess what a matrice éléphant is?)

PA Absil, Geneva, 20 April 2007