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[lyceum_arabica]

It turns out, and this is kinda crazy, but when you delete a row and a column from a matrix, it stops having the same eigenvectors. So, like, if you're trying to build something using the eigenvectors of the adjacency matrix of a graph (don't think about it too hard, it's weird), and you want the end product to be robust to the loss of a vertex in

Comments

[fox_n_flour]

come on, what did i tell you about writing posts in other languages?
the only words i understood in that whole thing were "all fucked up".
How can anyone help you when we can't even read what you wrote?
;-p

j/k of course. i also understood the words deleting, build, and robust. The last of which I know often has to do with coffee.

[lyceum_arabica]

So, it's like making a pie. Say you wanted to know what the true essence of an apple pie was, so you have several different recipes that all produce apple pie, and say you write the ingredient list for each recipe in the same order (so first it lists apples, then flour, then butter, etc... although the amounts might vary by recipe).

You start with the ingredients, do something like what's said in the recipes, and end up with a pie. But now, what happens if you're missing an ingredient? Like flour for instance.

What I'd forgotten, more or less, was that if you leave out the flour, and you follow the recipes, and you make a pie... the end product is not just a pie with no flour. You can't just throw a cup of flour on top and get a pie. The recipes combine the ingredients, so losing one of them affects the whole damn thing.

Like that, but with graphs and matrices. Sorta.

[oniugnip]

Ooh.

What's it mean to have eigenvectors of an adjacency matrix? Is that something that one can have an intuitive grasp on?

(of course, my intuition about eigenvectors in general is pretty much non-existent...)

[lyceum_arabica]

yeah, I've actually gotten a pretty good spiel down for it, but it requires gestures. :-) I'll tell you tomorrow. I'm apparently getting dropped off 5ish? Will you have the cats vaccinated by then? I was thinking of bringing our cats along for a brief encounter before everything gets too crazy.

[oniugnip]

I look forward to it :)

The guys are going for their checkup on Thursday. But they had their shots last spring; do you think they're vaccinated enough?

[lyceum_arabica]

I don't know... as I emailed lindsey, the main concern is that my cats have had feline flu, and it's a weird virus that stays dormant in the system rather than being killed off... so they remain carriers, and can be contagious whenever they're stressed. But you can get your cats vaccinated against it (my guys got it while they were on the streets).
So... mm... this is a bit problematic, logistically. We've still got the apartment through next friday, but it'll be empty... I wonder if you could get an appointment at college mall vets sooner?

[tiggerbone]

I would try to say something relevant, but my brain needs sleep.

Good luck!

[lyceum_arabica]

Merci :-) If after the sleep issue is resolved, you have any thoughts, let me know. Er. thoughts on this. Other interesting thoughts are ok too, within reasonable limits.