[buddhiajuke]

You’re not wrong.

OTOH the other day I heard someone in the Netflix doc about Alberto Nisman’s murder that described a terrorist network as a “matrix”.

I grumped as card-carrying pedants are duty-bound to, but then realized that if there’s a 1:1 correspondence between graphs and (adjacency, incidence) matrices, then there’s very little loss of meaning in referring to graphs as “matrices”. Maybe in some communication contexts it’s even clearer.

[uglycoyote]

That's funny, I would have just chalked it up to "they are using a different sense of the word matrix", knowing that most dictionaries contain multiple definitions of the same word. But nice work making this mental leap, I have never thought about it!

But it's true, you can envision it as a NxN matrix of N terrorists, where the number in cell i,j represent's the strength of the relationship (it's a weighted graph!), and that might actually be useful for something. I don't doubt that "matrix" might actually exist in numeric form in some CIA or military computer somewhere.

[microcolonel]

Maybe the term Disposition Matrix was more precise and less euphemistic than we were concerned it was. I guess you could compute a kill list from a genuine matrix of dispositions.

https://en.wikipedia.org/wiki/Disposition_Matrix

[a9h74j]

A few months ago I was imagining having a square matrix representation for fractions/attenuation of viral loads (e.g. per week) being transferred among a large population. I pictured a sum of isolated groups, after a sort, causing this larger matrix to be composed of a set of on-diagonal square submatrices.

[uglycoyote]

Yes I would think that you are dealing with sparse matrices with little clusters of nonzero values in a model like this.

One could say that I'm "part of a terrorist matrix", and that my value in the matrix is zero. We are all part of a terrorist matrix. I hope the CIA is not reading this, because they probably are not mathy enough to know what I'm talking about, and they may just take my quoted statement at face value, but in a mathematical sense we probably all actually have some nonzero value in our rows and columns of the terrorist matrix. You know someone, who knows someone, who knows someone, who is a terrorist. It really just depends how many people and how many degrees of separation you want to include in your matrix.