Apologies if this isn't an appropriate place to post this.

Inspired by a paper I found a while back (https://publications.lib.chalmers.se/records/fulltext/215545/local_215545.pdf), I tried my hand at implementing a program (in C#) to create ASCII art from an image. It works pretty well, but like they observed in the paper, it's pretty slow to compare every tile to 90-some glyphs. In the paper, they make a decision tree to replicate this process at a faster speed.

Recently, I revisited this. I thought I'd try making a neural net, since I found the idea interesting. I've watched some videos on neural nets, and refreshed myself on my linear algebra, and I think I've gotten pretty close. That said, I feel like there's something I'm missing (especially given the fact that the loss isn't really decreasing). I think my problem is specifically during backpropagation.

Here is a link to the TrainAsync method in GitHub: https://github.com/bendstein/ImageToASCII/blob/1c2e2260f5d4cfb45443fac8737566141f5eff6e/LibI2A/Converter/NNConverter.cs#L164C59-L164C69. The forward and backward propagation methods are below it.

If anyone can give me any feedback or advice on what I might be missing, I'd really appreciate it.

Hello everyone.

I am planning to get back into Linux development after working with Mac only for almost a decade. On Mac, one of the most important lessons that I learned was to always use Homebrew. Using various package managers (e.g. Homebrew, NPM, Yarn, Pip, etc.) creates situations in which you don't know how to uninstall or upgrade certain pieces of software. Also, it's hard to generate a complete overview.

How do you Linux folks handle this?

Bonus question: How do you manage your dotfiles securely? I use Bitwarden, and it's a bit clunky.

If that helps, I want to try Mint and always use Oh My ZSH!.

As the title suggests, I am looking for a free chrome or firefox plugin that can locally scrape data from multiple URLs. To be a bit more precise, what I mean by it:

• A free chrome or firefox plugin
• Local scraping: it runs in the browser itself. No cloud computing or "credits" required to run
• Scrape data: Collects predefined data from certain data fields within a website such as https://www.dastelefonbuch.de/Suche/Test
• Infinite scroll: to load data that only loads once the browser scrolls down (kind of like in the page I linked above)

I am not looking into programming my own scraper using python or anything similar. I have found plugins that "kind of" do what I am describing above, and about two weeks ago I found one that pretty much perfectly does what is described ("DataGrab"), but it starts asking to buy credits after running it a few times.

My own list:

• DataGrab: Excellent, apart from asking to buy credits after a while
• SimpleScraper: Excellent, but asks to buy credits pretty much immediately
• Easy Scraper: Works well for single pages, but no possibility to feed in multiple URLs to crawl
• Instant Data Scraper: Works well for single pages and infinite scroll pages, but no possibility to feed in multiple URLs to crawl
• "Data Scraper - Easy Web Scraping" / dataminer.io: Doesn't work well
• Scrapy.org: Too much programming, but looks quite neat and well documented

Any suggestions are highly welcome!

Edit: A locally run executable or cmd-line based program would be fine too, as long as it just needs to be configured (e.g., creating a list of URLs stored in a .txt or .csv file) instead of coded (e.g., coding an infinite scroll function from scratch).

New job. I've been wanting to learn something new for a while, so I took a project where a lot of React is done. I'm learning it from scratch while I work with React.

I have some comments about it.

1. React makes front end work a lot more like programming -- I like that!
2. Javascript has changed a lot, and for the better, since I last used it over a decade ago.
3. The React-Redux tool kit is the bomb. It should be integrated/absorbed into React. I can't see any reason not to use it, even for small applications as it is less wordy wherever you use it.
4. The updating of state values should be more automatic, especially for flag variables not tied to GUI components. It is the major source of hassles with React
5. Udemy React videos. My company makes them available free of charge to employees. I've sampled videos from a number of courses. I'm not a fan of the instructors showing you how to do things in older, less efficient ways first in a learning/demo project, the ERASING that code to do it a better way. The should include copies of the project at each stage if they do that. I finally figured out that the best way to take notes I can use later is to comment out the old code and put the new more efficient next stage stuff on top.
6. React tests really need to improve. They are often more time consuming than the code itself. The tests have forced me to change my code or do needless testing to get the tests to pass. I had one situation where no matter what I did React test said I didn't cover the code until I broke an else clause off into it's one if clause. Blech.

All in all I've been enjoying learning React. It is neat new ( to me ) thing.

I feel sad that I will likely forget it all when I go back to my specialty language.

Hey there,

I wanted to know which sets of passports grant together visa-free access to every country in the world, but I could not easily find that info online. So I figured that I could try to write a small program to determine these sets of passports myself, and then it occurred to me that it would probably be a fun programming challenge to organize, so here we go.

Here's the challenge.

1. Scrape the data you need for instance from The Henley Passport Index.
2. Design a clever algorithm to efficiently find out which are the smallest sets of passports that will grant you visa-free access to every country in the world.
3. Optional. Allow the user to specify which passports they already hold and find out which sets of passports would complement their passports well.
4. Optional. Rank the sets of passports by how easy it is to acquire citizenship in those countries.

The choice of the programming language is yours, bonus points if you write it in assembly 😂

Feel free to collaborate and share your solutions (the algorithms and the actual results) in the comments, and feel free to share your own twists to the challenge that could make it even more fun & interesting.

The person with the most clever, efficient and elegant algorithm wins!

Happy coding folks!

Just for a moment, forget all of the technical pros and cons, the static typing, just-in-time compilation, operator overloading, object orientation to the max...

Is there a programming language that you've just found to be... fun?

Is there one that you'd pick above all else for personal or company projects, if you had your druthers, because you would simply be so excited to use it?

And then, is there something missing in that "fun" language that's preventing it from actually becoming a reality (i.e. small community, lack of libraries, maintenance ended in the 80s, etc.)?

I am an experienced programmer (mostly M$ stack -- C#, etc).

I started learning mobile Android development a few months ago, learning both Kotlin and the larger Android development environment at the same time. I got bogged down in tutorials and guides, because half of them teach Jetpack Compose methodology and half teach XML layout ... and, often enough, don't bother to mention which method they're using.

Which should I learn first? I am initially interested in learning Android dev for my own hobby/fun/side projects, but I would--ultimately--like to be able to put "Android developer" on my resume.

Jetpack definitely looks better, more modern, more OO, and I expect it will eventually become the new standard ... but that could still be many years down the road. Also, while it might be "better"--especially for larger projects--it also smells more complicated.

So, ultimately, I guess I should learn both if I actually intend to become an Android dev ... but I should definitely get comfortable with one, first ... so, which one?

General Programming Q&A thread! Ask any questions about programming, answer the questions of other users, or post suggestions for future threads.

Don't forget to format your code using the triple backticks or tildes:

Here is my schema:

```sql
CREATE TABLE article_to_warehouse (
  article_id   INTEGER
, warehouse_id INTEGER
)
;
```

How do I add a `UNIQUE` constraint?