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Just published an interactive article about a magical algorithm known as the Burrows-Wheeler Transform, which powers sequence alignment tools like bowtie and bwa: sandbox.bio/concepts/bwt It's also notoriously unintuitive so I'm hoping this article helps you build that intuition.

Sam Rose

@samwho.dev

It’s not obvious to me what happens in this step. You say it “sorts the matrix” but I don’t see that at all. The two strings swap places and one completely changes to an order that is very much not sorted. What am I missing?

14/10/25, 6:00 am0 reposts0 likes

Robert Aboukhalil

@robert.bio

14 Oct 2025

Ah, by sorting the matrix, I meant sorting the set of 9 strings defined by each row of the matrix, not sorting the 2 strings defined by each column of the matrix.