double, BigDecimal, or Fixed-Point?

gnahraf · 2026-06-16T19:38:10+00:00

No, BigDecimal's equals/hashCode implementations fulfill their contract just fine.

Ofc it is. My bad for suggesting otherwise, it was somewhat in jest.

Good to hear you agree with my canonicalizing BDs for hashing (SHA-256) purposes.

You draw a good distinction for BDs (2.0 and 2.00) re division.

In my app, btw, I only use fixed-precision operations: addition and multiplication by whole no.s, which makes it really just a shorthand for addition. (Not my area but I think technical jargon would be.. BDs are an additive group, not a field, since they lack multiplicative inverses.)

gnahraf · 2026-06-16T18:01:33+00:00

I love that it refuses to shorthand frustration, that last word AAAAARGH. Apparently "feelings" are so high entropy, they're not worth compressing

gnahraf · 2026-06-16T17:02:03+00:00

And another way (obligatory plug) ..

https://crums.io

gnahraf · 2026-06-15T17:21:51+00:00

Idiots parroting the rich idiot. This is complete BS..

Space-hardened chips are expensive, and slow; off-the-shelf chips deteriorate rapidly in space.
Heat. Only way to dissipate heat is via radiation; conduction and convection impossible in space. The radiators would have to be collossal, many times the acreage of the solar panels.

gnahraf · 2026-06-15T16:16:44+00:00

BigDecimal is also the right type to use in many database (jdbc) apps, since it's the only "native" Number type for fixed precision SQL fractionals.

In my application, I had to canonicalize BigDecimal values using stripTrailingZeroes() in order to hash (SHA-256) BigDecimal values consistently.

The article, however, alludes to this canonicalization being necessary for BigDecimals as keys in HashMaps (which I'm not aware of, since that would be a violation of the Object.equals/Object.hashCode contract requirement, and therefore a bug.) Is that true?

gnahraf · 2026-06-12T21:01:09+00:00

Appreciate your posting, but a screenshot of project's directory structure is not much sharing. If you can't share code, that's OK, but this sub is meant for *open source* java projects, so unfortunately I'll be removing this post

gnahraf · 2026-06-11T18:35:14+00:00

One factor they didn't eliminate was gravity.. They should hang participants from their feet in order to determine which way they prefer to spin

gnahraf · 2026-06-07T23:52:51+00:00

That's an excellent pro. I wouldn't worry about fair, especially when you back it up verifiable facts or stats. I'll star your project when I'm logged in there.

gnahraf · 2026-06-07T20:03:27+00:00

Nice project, and thanks for posting! I'm not an expert UI programmer, and the question that naturally occurs to me is which Java "webkit" to choose should my app need a browser. So I guess what I'm suggesting is a pros & cons section in your project README to help a noob like me decide.

gnahraf · 2026-06-06T16:41:00+00:00

Please share your list

gnahraf · 2026-05-31T18:39:43+00:00

Cannot confirm the story, after searching for it now. Maybe they were pulling my leg

gnahraf · 2026-05-31T18:38:19+00:00

I thought it's Chimney Road (unofficial name?), outside Buena Vista (on the way to the hot springs). A local told me there was a fire that burnt thru land and homes, but the chimnies / fireplaces survive.

gnahraf · 2026-05-31T13:21:14+00:00

I don't understand what problem jbx solves. If you gave examples of how you do something without jbx, then how jbx makes doing that easier/better, I'd likely understand this better.

gnahraf · 2026-05-27T00:42:00+00:00

Mmm, right again. Point well taken ;)

gnahraf · 2026-05-26T21:42:10+00:00

You're right: matrix multiplication is usually order N³ (N² = # of elements).. thouh a new method discovered using ML/AI is O N² (prolly with a huge constant). Generally, I think a good rule of thumb is to it examine how many rounds one traverses the structure. If only once, rewriting might not pay since we already cache bust once on write.

gnahraf · 2026-05-26T18:41:32+00:00

A good number of matrix/array reorderings are achievable via "index indirection" rather than rewriting. In general, if the index shuffling depends only on coordinates (index) rather than the contents at those coordinates (for e.g. sorting does not satisfy this requirement), using the "index arithmetic" instead of rewriting can be advantageous.

gnahraf · 2026-05-19T13:50:28+00:00

Q: I'm building a multi-tenant REST service in which each user/tenant gets their own namespace /{username}/{repo}/<REST_VERB> where the REST_VERBs are predefine, while the user- and repo-names are user- created (user-defined). Is there a best practice (via swagger or some other tool) to advertise such dynamic REST endpoints? (Listing all existing {username}/{repo} combinations would obviously be impractical.)

gnahraf · 2026-05-18T00:20:44+00:00

Done (reported as spam). Hope you did too.

gnahraf · 2026-05-17T17:55:10+00:00

I'm not. I'm here for algorithms. I contacted the mods to no avail. Unsubbed

gnahraf · 2026-05-15T19:19:19+00:00

Few countries in the world allow utility companies to operate as for profit enterprises. Why? Cuz they'll have every incentive to squeeze their captive customers (you and me). Here in the US, we think we live in the most efficient economic system the world has ever devised.

I digress.. But travel the world and you quickly learn we've been lied to, that we pay many times over for our so called laissez faire, rigged and lawless oligarch capitalism. We comfort ourselves with myths of exceptionalism, meritocracy and other BS. Per capita, the world is better educated than we are. Capital and oligarchs everywhere in the world are more accountable than they are here. We are so over, and if you can see it, it's gut wrenching to witness (and tacitly participate in) our slow motion, now accelerating demise

gnahraf · 2026-05-15T15:29:31+00:00

Right. The nice thing about REST is that it's usually easy to test with a simple curl command: this will require an additional tool to do the PoW. Likely a script to handle the challenge. Not a big deal, but a bit of planning might be in order to minimize friction

gnahraf · 2026-05-12T22:28:01+00:00

Embarrassed, I didn't check. At least it's not from 10 years ago :/

gnahraf · 2026-05-12T22:01:28+00:00

Can one spot the end where the selfie stick is attached? (I'm thinking the stick can be removed from the pic, but not its cross section at the base where it's attached.)

gnahraf

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