Popular Posts

Popular Content

Powered by Blogger.

Search This Blog

Follow on Google+

Recent Posts

About us

Hi HN! I've posted Pickcode a few times (most recently https://news.ycombinator.com/item?id=38365638), but we've improved things quite a bit so I thought it was worth posting again. This is a bit of 1.0 release after a long year of working on the company full time!

Pickcode is basically Replit-lite, for kids. The editor is simple: text editor + output console + big green button to run your code. We support Python, HTML/CSS/JS, Java, and our block/text hybrid language, Pickcode VL. We're partners on code.org's Hour of Code, and hundreds of thousands of students have tried our free stuff through them.

An account for individual kids is totally free, and we offer some free Python and Pickcode VL lessons to get them started. We make money by selling licenses to schools for better customer support and roster/lesson management features.

You can use this demo account I made to try out the editor:

  email: demo@student.pickcode.io
  pw: Demo1234
(Don't clobber other people's work, and what you put in the demo account is public so be nice)

Comments URL: https://news.ycombinator.com/item?id=40831904

Points: 16

# Comments: 3



from Hacker News: Front Page https://pickcode.io
Continue Reading

Article URL: https://retrocomputing.stackexchange.com/questions/30261/what-actual-purpose-do-accent-characters-in-iso-8859-1-and-windows-1252-serve

Comments URL: https://news.ycombinator.com/item?id=40820098

Points: 5

# Comments: 1



from Hacker News: Front Page https://retrocomputing.stackexchange.com/questions/30261/what-actual-purpose-do-accent-characters-in-iso-8859-1-and-windows-1252-serve
Continue Reading

Hey HN,

I'm about to take lead of a decent sized software migration at work. (From V1 of some subsystem, to v2, both in house. We want to deprecated and eventually remove V1 totally) For 8 of our clients, totalling about 16 million customers.

I don't have too many details to share, as I don't know what's relevant. But I'm asking if anyone has any advice or recommended reading regarding such?

One book that is really inspiring me about it is "how big things get done" by Bent Flyvbjerg and Dan Gardner. In it, there's some key bits of advice such as

* Think slow, ask fast, and mitigate long tailed risks.

* Compartmentalize and stick to repeated processes. "Build with LEGOs"

* Look around at other projects of similar nature.

The last point is why I'm here, as I know some of you have been in the game for longer than I have, so feel free to share experiences that you might think is relevant, if you'd like.


Comments URL: https://news.ycombinator.com/item?id=40757486

Points: 14

# Comments: 10



from Hacker News: Front Page https://ift.tt/b9gL4Zc
Continue Reading

This is the third camera I've designed/made around the raspberry pi parts/ecosystem.

The repo has all the STL files, parts list, most wiring diagrams. The first one was the custom Pi Zero HQ cam which was featured on a Hackaday article/podcast.

The modular version (aside from being able to swap cameras) mostly has the latest software. Recently I added the ability to process videos in the background (ffmpeg merges wav/mp4 files together).

The camera uses crop-zoom-panning for dialing in shots with manual lenses. The menu is created by layering images/text with PIL. Live preview is a little slow as it's SPI based.

If anybody is a pro at python I'd appreciate insight on better code. I've mostly just followed a context-based folder layout regarding where everything is.

I have not added custom/manual settings yet, it uses auto settings for the most part except for when you use a V3 camera module (which has electronic aperture) then it uses the d-pad to set the focus/diopter value.

I have another camera in mind/future build although it's more tailored for videos.

Some sample video I've shot.

https://www.youtube.com/watch?v=JkjXkQD0j9w

Assembly video

https://www.youtube.com/watch?v=dXG-MoIw93Q

At some point I will rewrite the code for a new general purpose DIY camera software from what I've learned, that'll be an undertaking.


Comments URL: https://news.ycombinator.com/item?id=40730245

Points: 19

# Comments: 6



from Hacker News: Front Page https://ift.tt/acGFUNp
Continue Reading

Pardon the vague question, but KDB is very much institutional knowledge hidden from the outside world. People have built their livelihoods around it and use it as a hammer for all sorts of nails.

It's also extremely expensive and written in a language with origins so obtuse that it's progenitor APL needed a custom keyboard laden with mathematical symbols.

Within my firm, it's very hard to get an outside perspective, the KDB developers are true believers in KDB, but they they obviously don't want to be professionally replaced. So I'm asking the more forward leaning HN.

One nail in my job, is KDB as a data-lake and I'm being driven nuts by it. I write code in Rust that prices options. There's a lot of complex code involved in this, I use a mix of numeric simulations to calculate greeks and somewhat lengthy analytical formulas.

The data that I save to KDB is quite raw, I save the market data and derived volatility surfaces, which are themselves complex-ish models needing some carefully unit-tested code to convert in to implied vols.

Right now my desk has no proper tooling for backtesting that uses our own data. And I'm constantly being asked to do something about it, and I don't know what to do!

I'm 99% sure KDB is the wrong tool for the job, because of three things:

- It's not horizontally scalable. A divide and conquer algo on N<{small_number} cores is pointless.

- I'm scared to do queries that return a lot of data. It's non trivial to get a day's worth of data. The query will just often freeze, it doesn't even buffer. Even if I'm just trying to fetch what should be a logical partition, the wire format is really inefficient and uncompressed. I feel like I need to engineering work for trivial things.

- The main thing is that I need to do complex math to convert my raw data, order-books and vol-surfaces into useful data to backtest.

I have no idea how do do any of this in KDB. My firm is primarily a spot desk, and while I respect my colleagues, their answer is:

> Other firms are really invested in KDB and use KDB for this, just figure it out.

I'm going nuts because I'm under the assumption that these other firms are way larger and have teams of KDB-quants doing the actual research. While we have some quant traders who know a bit of KDB but they work in the spot side with far more simple math.

I keep on advocating for some Parquet style data-store with Spark/Dask/Arrow/Polars running on top of it that can be horizontally scaled and most importantly, with Polars, I can write my backtests in Rust and leverage the libraries I've already written.

I get shot down with "we use KDB here". I just don't know how I can deliver a maintainable solution to my traders with this current infrastructure. Bizarrely, and this is a financial firm, no one in a team of ~100 devs has ever touched Spark style tech other than me here.

What should I do? Are my concerns overblown? Am I misunderstanding the power of KDB?


Comments URL: https://news.ycombinator.com/item?id=40625800

Points: 14

# Comments: 13



from Hacker News: Front Page https://ift.tt/VRNpOzy
Continue Reading

This is a project I've wanted to write for a long time now. I really love the ideas from Nix and I still have a ton of respect for the project, but Nix-the-language never felt intuitive to me and I wanted something with more approachable tooling (although this was circa 2016, so I'm sure Nix has improved a lot since then too-- that was before Flakes were around!)

Anyway, I started on the current iteration of Brioche about 6 months ago, and I finally cut an initial release. I'd still consider this a "technical preview" version (performance especially is pretty painful, so that'll be a focus of mine in the coming weeks). But it's finally at a point where it does work end-to-end and folks can take it for a test drive!


Comments URL: https://news.ycombinator.com/item?id=40563984

Points: 9

# Comments: 0



from Hacker News: Front Page https://ift.tt/ZN7m9Yv
Continue Reading

A bit more context - the cloth sim is part of my app, Lungy (https://www.lungy.app). It's designed to be an active meditation / relaxation app, so you can play relaxing instruments in space and immersive breathing exercises. The original Lungy is a breathing app available for iOS, that uses real-time breathing with interactive visuals.

The cloth sim is a Verlet integration, running on a regular grid. For now, I have tried a couple of different cloth scenes - a sort of touch reactive 'pad', where different parts of the cloth are mapped to different sounds and a cloth that blows in sync with breathing. The collision detection is a little bit tricky with the deforming mesh, but seems to work ok overall. Overall, it seems like a cool interaction to explore.

The cloth sim is live on the app store now (and free) - would love to hear feedback from anyone with a Vision Pro.

App Store (Vision Pro): https://apps.apple.com/app/id6470201263

Lungy, original for iOS - https://apps.apple.com/app/id1545223887


Comments URL: https://news.ycombinator.com/item?id=40539800

Points: 5

# Comments: 1



from Hacker News: Front Page https://www.youtube.com/watch?v=kpD2J85WjzM
Continue Reading