davidcuddeback

Joined 17 years ago

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Member since

Oct 10

My name is David Cuddeback. My email address is <my-first-name> DOT <my-last-name> AT gmail DOT com

Or in BNF if you prefer:

    email      ::= <full-name> "@" <domain>
    full-name  ::= <first-name> "." <last-name>
    first-name ::= "david"
    last-name  ::= "cuddeback"
    domain     ::= "gmail.com"

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Recent submissions

Comment · 2 years ago

> Would you use the Builder pattern if the language had named variables in arguments?

Yes, absolutely. I see it all the time in the Ruby ecosystem and have used it myself in Ruby. Many times it gets called by a different name. I've seen it in Python and Elixir too.

Comment · 2 years ago

> On the other hand, what's the chance of something like this happening with a much bigger asteroid.

Bigger asteroids are easier to see.

Comment · 2 years ago

Sure thing! I'd reframe this as a nearest neighbor search over (start time, duration) tuples. KD trees are what I'm most familiar with for that problem, but there are others that would fit. Check out chapters 1 ("Multidimensional Point Data") and 3 ("Intervals and Small Rectangles") of Foundations of Multidimensional and Metric Data Structures: https://books.google.com/books?id=vO-NRRKHG84C&pg=PR9&source...

R-trees are more generic in that they can store intervals, shapes, volumes, etc, but (start time, duration) tuples are point-like, and that opens more possibilities. The ordered map is going to give you good memory locality. It might be that you'll only beat that when searching for larger durations (that require you to iterate over more of your ordered map). There will probably be an inflection point somewhere, depending on the distribution of your data and queries.

Hope that helps!

Comment · 2 years ago

Elsewhere is the thread, it sounds like your range queries with inequality constraint might actually be a nearest neighbor query with inequality constraint. I'm not sure off the top of my head how feasible that would be with a priority search tree.

Comment · 2 years ago

"Nearest gap" doesn't sounds like a range query to me. It sounds more like a nearest neighbor query. It sounds like you have (start time, duration) tuples and want to search for nearest neighbor on start time with an at-least-X constraint on duration. (start time, duration) is more point-like than interval-like (as far as data structures go), so anything that can handle nearest neighbor on point-like data would be a candidate. If this is an accurate mapping for your problem, you might check out KD trees. You'd probably have to write a custom tree traversal algorithm to query NN on one dimension and >X on the other, but I think it could be done. Sounds kinda fun.

Comment · 2 years ago

> Many range queries also have a minimum duration requirement, so it could be useful if a data structure could take advantage of this to quickly exclude intervals during the search.

Check out priority search trees. They search two dimensions, one of them being half-open (that would be your minimum duration requirement). Depends if the other half of your queries fits the closed dimension of a priority tree or if you can adapt it to fit your needs.

Comment · 2 years ago

It's really going to depend on the queries that you want to optimize. I think the best help might be to point you to a book: https://www.amazon.com/Foundations-Multidimensional-Structur...

An RTree is the first structure that comes to mind, but the way you describe the problem, it sounds like the intervals never overlap, so I have my doubts. Sounds like you might be looking to optimize the query "what is the first interval of at least N days?" Maybe look at priority trees. They're good at queries that are bounded in one dimension and half-open in the other.

Comment · 2 years ago

Case in point: the same equations predict white holes, which today are widely believed to not exist.

Comment · 2 years ago

I am taking kids out of school for a few days and driving 13 hours to a cabin that I rented on a lake on the centerline. It helps that my 40th birthday is within a couple days of the eclipse.

Comment · 2 years ago

I've looked into some workshops, including his. It's not in the cards for me now, but something I'd like to do someday. I also enjoy coming back to the central coast (I went to college in SLO). Jory did some videos on his Hollister credenza for the TWW Guild. They captured (possibly unintentionally) the laid back central coast vibe with the open doors and the birds chirping in the background.

Comment · 2 years ago

Jory Brigham?

Edit: Nevermind. Answered down thread. Lucky you. Beautiful area and Jory's work is phenomenal.

Comment · 2 years ago

I'm not sure about the history of these words, but astronomy also uses the noun form: "occultation" [1], for which there's not an obvious equivalent for "occlude."

> Did occult mean what it does now when they started?

A word can have more than one meaning. The first definition on merriam-webster.com covers the definition used in astronomy:

occult (v.): to shut off from view or exposure: cover, eclipse [2]

The adjective form might be a source of derivation for the meaning you're alluding to:

occult (adj.): (1) not revealed: secret; (2) not easily apprehended or understood: abstruse, mysterious; (3) hidden from view: concealed [2]

And finally, the paranormal meaning that people are more familiar with today:

occult (n): matters regarded as involving the action or influence of supernatural or supernormal powers or some secret knowledge of them -> used with the [2]

Again, I don't know the history of these words. If I had to hazard a guess, I'd bet that the noun form, "the occult", is derived from the adjective form since "the occult" refers to supernatural phenomena, which is naturally hidden from view, concealed, not revealed, secret, not easily apprehended or understood, etc (because it's not real).

Edit: Another guess. If you think about the history of astronomy, it was originally intertwined with religion and astrology. Perhaps these words date back to a time when "the occult" and astronomy weren't entirely separate. Anyways, I agree. Language is strange.

[1]: https://en.wikipedia.org/wiki/Occultation

[2]: https://www.merriam-webster.com/dictionary/occult

Comment · 3 years ago

Physical can be understood to mean "of or relating to matter and energy or the sciences dealing with them, especially physics." Light, temperature, and time are described by physics, so I would consider "physical" to be an accurate adjective for those units. You seem to be using a more limited definition of physical, closer to the word "spatial."

Also, btw, you might want to read the article you linked. The article is discussing a fringe idea that some scientists have. Scientists are free to explore new ideas, and they make for good click bait for science journalists. Until those ideas gain traction, they don't provide for compelling arguments, though.