[sago]

I thought the same, and as per fovc's comment, below, I think what their statistical analysis did was basically a coarse fourier transform.

In the Harry Potter example you can see that a higher frequency is very significant. But the exact frequency is probably rather arbitrary from book to book, whether there are ten peaks or five, say. So I'd imagine, over lots of texts, any particular higher frequencies is less significant, leaving the lowest modes to dominate, as you point out.

So overall, a rather uninspiring result, I felt.

Though if we're both missing something, it would be good to know!

[hbosch]

A note some HNers might find tangentially interesting: in David Foster Wallace's Infinite Jest, Fourier transforms are a bedrock concept for the titular entertainment, which is considered such a perfect piece of media that it is lethally addictive. How nice it was to see this post about "shapes of narrative" be compared to Fourier transforms for a IJ nerd!

[Pyramus]

Very uninspiring indeed!

Let me know if you are interested in investigating this properly.