Hacker News: _fbpt

New comment by _fbpt in "The Polygons of Another World: Atari Jaguar"

_fbpt — Fri, 13 Mar 2020 22:20:23 +0000

The URL links to the #back_1 anchor/id and ends up half a page down.

New comment by _fbpt in "Building Spectro: a Real-Time WebGL audio spectrogram visualizer"

_fbpt — Sun, 08 Mar 2020 21:45:03 +0000

> The signal will continue over the seam between two windows, meaning you will cut the wave in the signal "in half".

You can window the wavelet, then slide the finite-duration wavelet by a few samples at a time, even if the wavelet is hundreds to thousands of samples long. This is possible in STFT as well (each part of the original signal shows up in many separate FFTs).

Again, I don't know the implementation details of wavelet transforms. Maybe I'll look into your repo when I have time. What's your asymptotic and practical runtime?

New comment by _fbpt in "Building Spectro: a Real-Time WebGL audio spectrogram visualizer"

_fbpt — Sat, 07 Mar 2020 12:26:54 +0000

I'm more familiar with Fourier transforms and have limited experience with wavelets. But if each wavelet intrinsically falls off at a Gaussian curve, cutting it off (possibly with a window) at 3-4 sigmas won't change the wavelet substantially. Maybe for some use cases, the wavelet will be narrower at high frequencies (short delay), and wider at low frequencies (high delay). I don't know how you'd perform incremental updates of a plot drawn with non-uniform delays though...

New comment by _fbpt in "Building Spectro: a Real-Time WebGL audio spectrogram visualizer"

_fbpt — Sat, 07 Mar 2020 01:21:57 +0000

Your repo and tutorial are really cool! But do you have any sort of interactive "out-of-the-box" demo that doesn't require me to write code to call the library (online or downloadable)?

New comment by _fbpt in "Clojure: A Lisp that wants to spread"

_fbpt — Mon, 02 Mar 2020 01:44:09 +0000

> A 64-bit capable JDK currently ignores this option and instead uses the Java Hotspot Server VM.

New comment by _fbpt in "Show HN: A first project in Rust – in-memory order book"

_fbpt — Sat, 22 Feb 2020 13:35:14 +0000

Is wrapping a String in a semi-opaque newtype (or a type alias at least) good to encode the semantic meaning of the string type?

New comment by _fbpt in "Move, simply"

_fbpt — Tue, 18 Feb 2020 01:26:22 +0000

Is the intention of std::move that the "moved-from" pointer no longer has its destructor run?

What if you move a unique_ptr from a std::vector? You don't know which elements of the vector need to have their destructors run.

I think Rust unconditionally doesn't run the destructor of a moved-from Box, but uses drop flags for "maybe-moved-from" local variables, and doesn't allow maybe-moved-from Vec elements.

New comment by _fbpt in "SciPy 1.0: fundamental algorithms for scientific computing in Python"

_fbpt — Tue, 11 Feb 2020 07:58:48 +0000

I agree with your comment to some extent. I'm kinda allergic to writing loops, even in C++ where it's the best solution.

On the other hand, in C++, hand-rolled matrix multiplication is both slower and an order of magnitude less accurate than MKL (or possibly OpenBLAS too).

New comment by _fbpt in "The Shadow Inc. app that failed in Iowa last night"

_fbpt — Wed, 05 Feb 2020 06:05:31 +0000

In particular it looks like Firefox Fenix/Preview (or possibly Reference Browser), not Fennec (regular Android). Only Fenix and Reference have bottom URL/tab bars. Fenix has a purple "Try Again" button, I don't know about Reference Browser, and Fennec has a gray button.

One possible issue is that Fennec/Fenix doesn't open http URLs in external apps by default (unsure about custom protocols), whereas Chrome does.

New comment by _fbpt in "Why Discord is switching from Go to Rust"

_fbpt — Tue, 04 Feb 2020 22:39:42 +0000

Both of these requirements kinda remind me of Microsoft's Verona language.

New comment by _fbpt in "Deanonymizing Tor Circuits"

_fbpt — Sun, 02 Feb 2020 00:51:11 +0000

The embedded images are ugly because of the downscaling (the URL contains &size=600).

New comment by _fbpt in "Why I Keep a Research Blog"

_fbpt — Mon, 13 Jan 2020 14:14:16 +0000

This seems to be a static site generator.

http://gregorygundersen.com/blog/2020/01/12/why-research-blo... has a HTTP header last updated on 01/13/2020 04:34:31.

http://gregorygundersen.com/blog/2019/12/23/random-fourier-f... is 01/13/2020 04:34:30, or 1 second earlier.

Also the source code has a link to http://gregorygundersen.com/css/markdown.css which 404's.

New comment by _fbpt in "Pijul: a distributed version control system, written in Rust (2019)"

_fbpt — Mon, 13 Jan 2020 13:44:46 +0000

https://github.com/mhagger/git-imerge

> Reduce the pain of resolving merge conflicts to its unavoidable minimum, by finding and presenting the smallest possible conflicts: those between the changes introduced by one commit from each branch.

I'm not sure this would've helped in my scenario. famitracker had no public repo, and the Qt fork and 0cc-famitracker came from different Git repositories and were rooted in different subdirectories. I created a synthetic Git and Pijul history for the purpose of this merge.

But it might be helpful in other situations. I'll look into it.

> Allow a merge to be saved, tested, interrupted, published, and collaborated on while it is in progress.

This does seem useful.

New comment by _fbpt in "Pijul: a distributed version control system, written in Rust (2019)"

_fbpt — Sun, 12 Jan 2020 10:49:28 +0000

About half a year ago, I tried to merge two forks of a single program which had diverged by several years. I tried a Git merge, got halfway through conflict resolution, stashed my current changes and reset my repository, and could not reapply my partial resolution. (The proper approach would've been to manually run `git rerere` without arguments to save the current partial resolution, but I didn't know that).

I redid the merge in Pijul. Pijul had a bug causing it to misread the filesystem's execute bit, and no amount of `pijul reset` would fix it. Pijul's merge conflict textual syntax was baffling as well. I think it was a stack which was pushed and popped by >>> and <<< markers, and anything under === was something I should probably remove. In the end, I did succeed in the merge, but reconciling the two projects didn't work out.

(FamiTracker was based off the MFC GUI library. It was forked to 0CC-FamiTracker, and another fork ported it to a MFC compatibility layer with a cross-platform Qt backend. The MFC compatibility layer didn't support all the functionality used by 0CC-FamiTracker.)

New comment by _fbpt in "I don’t know if whoever flagged the typos in my eBook thought they were helping"

_fbpt — Wed, 25 Dec 2019 00:45:12 +0000

> Since there was no redline provided, it took my friend hours to go back and fix all of their errors (there were other formatting changes that had to stay, otherwise they could have just reverted to the prior version).

Was your friend able to use a program to diff (show all changes between) the two versions, and resolve them? Or was it done by hand?

New comment by _fbpt in "This Page is Designed to Last"

_fbpt — Fri, 20 Dec 2019 02:02:47 +0000

WorldBrain's Memex (https://addons.mozilla.org/en-US/firefox/addon/worldbrain/) has an option to perform a full-text index (not archive) of bookmarks, or pages you visited for 5 seconds (default) down to 1 second (no option to index all pages). It stores this stuff into a giant Local Storage (etc) database, which Firefox implements as a sqlite file.

New comment by _fbpt in "We 30x'd our Node parallelism"

_fbpt — Fri, 13 Dec 2019 16:52:07 +0000

When I try to view the image in a new tab, I get:

Your client does not have permission to get URL /Iw-RdHoPjbwuSAqJHK3C0Sy8m29NqzeHPtmJ7CVFuYqwr4CbwpGjwn9O4bcDNtCf_hLD4FGc75nkQYnJBgyA-CT2ikBDWQD-nAtqxXa4Lw2yDuh_-ywcsDaer6m4LyVtljwfrajO from this server. (Client IP address: [redacted])

Rate-limit exceeded That’s all we know.

New comment by _fbpt in "Layered Programming (2013)"

_fbpt — Wed, 11 Dec 2019 21:19:12 +0000

Fascinating idea. I've definitely written and encountered programs where functions were more complicated than they could've been, in order to support features separate from the "main idea" of the program. Like FPS calculation, Ctrl+C handling, passing intermediate audio data to extra buffers for visualization...

Could "splicing in" code it be implemented using aspect-oriented programming frameworks? https://en.wikipedia.org/wiki/Aspect-oriented_programming I've never used them though.

> There's a new constraint that has no counterpart in current programming practice — remove a feature, and everything before it should build and pass its tests: > build_and_test_until

Looks like added tooling is needed, but seems worthwhile.

New comment by _fbpt in "O(n^2), again, now in Windows Management Instrumentation"

_fbpt — Tue, 10 Dec 2019 13:41:33 +0000

When was this story from? From my limited knowledge, I think persistent hashmaps have been available since Clojure 1.0 (2009) or before? (hash-map, https://clojure.github.io/clojure/clojure.core-api.html#cloj...).

New comment by _fbpt in "A walk through the Magit interface"

_fbpt — Mon, 09 Dec 2019 20:46:00 +0000

Git Extensions and Git Cola (possibly other GUI clients I haven't used) have the ability to view a diff and stage individual lines from it. Unfortunately they don't let me reorder lines in the diff.