I can’t remember exactly how I ended up at the Lost Clock Emporium. I do remember brushing by disturbed looking people making their way out.

“Clock a load of you!”, the proprietor muttered, before looking up. “No time to waste, I have things to show you.”

If you’re working with image processing and discrete Fourier transforms (frequency analysis/filtering)¹ you need test images, and possibly even videos.

Xor Xor Gabor² is my name for an easy to make test image (and video) that is a nutritious source of frequencies:

More on Ohmaps: component failure battles, limitations, ambiguity…

Disclaimer: I am not an electrician. Nothing here is electrical advice/expertise. Insure your garments.

Occasionally there’s a lovely moment when I’m working on a problem and I realise I’m also looking at some other thing that seems completely unrelated. It’s like a metaphor made flesh.

These ‘isomorphism moments’ can be powerful because the two seemingly unrelated things can give you insights into each other. Their commonality encourages you think about the essential thread running through them both.

This post details one of these moments I had recently.

Introducing the simplex generator for higher dimension pascal/combinatorics and looking at the bigger picture: exhaustive function composition.

This is the first of a few notes about combinatorics and probability. Simpler concepts first, and eventually might get to stuff like analytic combinatorics.

I’m interested in the point where more simple combinatorics and multinomials become blunt tools and we have to move to higher concepts like generators and species.