jwmerrill

8 ms·

31.
by jwmerrill 6y ago
I sometimes wish there was a way to demand the same level of proof for claims of readability and productivity that we demand for claims about performance. Measuring before optimizing is of course a good idea, but it's also time consumi
32.
by jwmerrill 7y ago
This is a lovely essay, but I think it goes a little too far in claiming that the electromagnetic field is intangible or immeasurable, in slightly forced analogy with quantum mechanics. > We now take it for granted that electric and magn
33.
by jwmerrill 7y ago
The default calculator on Android since Marshmallow apparently uses arbitrary precision arithmetic: https://m-cacm.acm.org/magazines/2017/8/219594-small-data-co...
34.
by jwmerrill 7y ago
Yes, you’re right about the minute hand. Oops. “arch minute” is a term used in the article, but “arc minute” also sounds more standard to me.
35.
by jwmerrill 7y ago
To make it even more concrete: realize that the hour hand on a clock moves 6 degrees per minute (it takes 60 minutes to go all the way around, 360 degrees). This study claims that variations of the earth’s magnetic field direction that are
36.
by jwmerrill 7y ago
This study hinges on binning by variability of the magnetic field. It’s important to realize how small these variations are. The authors measure variation in the field direction in “percent”, but the units are arch minutes (1/60 of a d
37.
Flattening Quadratic Béziers(raphlinus.github.io)
100 points by jwmerrill 7y ago|6 comments
38.
by jwmerrill 7y ago
> "I’m also not aware of any calculator (or programming language) that currently works this way." [represent fractions exactly wherever reasonable to do so] Author here. The paraphrase makes this sound wrong, but what I actuall
39.
by jwmerrill 7y ago
You might like some of the other posts on the blog! I’ve written several other posts showing how Geometric Algebra can be used in plane geometry problems that would typically be treated with lengths and angles. Most recent post, which links
40.
More Intuitive Calculator Arithmetic (2018)(engineering.desmos.com)
50 points by jwmerrill 7y ago|21 comments
41.
by jwmerrill 7y ago
> 355/113 is more precise 1/(113^2) ~ 0.00008 and the fraction is still possible to be stored in 16-bit log2(355)+log2(113)≈15.3, so it seems like you could squeeze this into 16 bits, but what about a sign bit? And since 355&gt
42.
Extending the Algebraic Manipulability of Differentials(arxiv.org)
2 points by jwmerrill 7y ago|0 comments
43.
More Intuitive Calculator Arithmetic(engineering.desmos.com)
1 points by jwmerrill 8y ago|0 comments
44.
by jwmerrill 8y ago
> even Einstein didn't remember how to do long division, he looked it up Nitpick: the idea that Einstein struggled with school-level mathematics is a myth[1]. I would be very surprised if he ever had to look up the procedure for lon
45.
How Desmos uses Pratt Parsers(engineering.desmos.com)
51 points by jwmerrill 8y ago|6 comments
46.
by jwmerrill 8y ago
Typescript has flags for turning on more strictness, and I highly recommend using them. For example, strictNullChecks for your example above. There’s a “strict” flag that you can use to turn on most of the more specific strictness flags all
47.
More Intuitive Calculator Arithmetic(engineering.desmos.com)
1 points by jwmerrill 8y ago|0 comments
48.
by jwmerrill 8y ago
Good to know. I think the writing in this article is not so good, but I've seen this usage by plenty of respectable writers. Stephen Hawking's "A Brief History of Time" is not comically bad writing, and it's full of
49.
by jwmerrill 8y ago
I think 200 million million is a British English thing because of the long scale/short scale ambiguity: https://en.m.wikipedia.org/wiki/Long_and_short_scales
50.
California Passes Sweeping Law to Protect Online Privacy(nytimes.com)
1 points by jwmerrill 8y ago|0 comments
51.
Inside the Knotty World of ‘Anyon’ Particles(quantamagazine.org)
1 points by jwmerrill 9y ago|0 comments
52.
by jwmerrill 9y ago
According to Wikipedia, Mathematica was initially released in 1988. Rebol was first released in 1997. Maybe Rebol inspired some part of Mathematica that came later, like the manipulate/dynamic system?
53.
by jwmerrill 9y ago
Looks like grandparent probably meant g(x) = x/√(1+x²) Looks like f(x)=x+x^3/5 gets you two decimal digits everywhere [1], and you could improve that with more terms in the polynomial. Edit: you can derive f(x) by doing a series e
54.
by jwmerrill 9y ago
This is a misunderstanding of Carnot cycle efficiency. The thing that makes the Carnot cycle special is that it is reversible. So in principle, you can get 100% of the mechanical energy that you put in back out again, by running the process
55.
by jwmerrill 9y ago
It's probably a law of nature that prices won't stabilize somewhere where you could triple the price and sell 1/3 the quantity. At the higher price, revenue would be the same, but you only had to produce 1/3 of the goods
56.
by jwmerrill 9y ago
These are good points in general, but I don't think they're relevant to the author's partitioning of PI to get extra precision near the zeros. The article does a good job of explaining exactly what's going on here, and h
57.
by jwmerrill 10y ago
It's much easier to get an intuitive understanding of convolution directly in the time domain, without worrying about Fourier Transforms. Convolution with a top-hat kernel is just a moving average. Each point of the output is the avera
58.
by jwmerrill 10y ago
It was open source before we started using it, but we're friends with the creators, so I can pass on the compliment.
59.
by jwmerrill 10y ago
I wonder if it's gotten better since 2002-2004, which is when I used it a lot. I'd be curious to hear what you think about the equation editor in Desmos[1] (full disclosure, my employer). We use an open source WYSIWYG typesetting
60.
by jwmerrill 10y ago
To everyone who says "why do we need this when we have LaTeX?" I ask the question "why do we need Markdown when we have HTML?" The nice thing about Markdown is that it's quite legible in its source form, which makes

More ›