I write code and play games and stuff. My old username from reddit and HN was already taken and I couldn’t think of anything else I wanted to be called so I just picked some random characters like this:

>>> import random
>>> ''.join([random.choice("abcdefghijklmnopqrstuvwxyz0123456789") for x in range(5)])
'e0qdk'

My avatar is a quick doodle made in KolourPaint. I might replace it later. Maybe.

日本語が少し分かるけど、下手です。

Alt: e0qdk@reddthat.com

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  • 50 Comments
Joined 1 year ago
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Cake day: September 22nd, 2023

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  • It’s not a GUI library, but Jupyter was pretty much made for the kind of mathematical/scientific exploratory programming you’re interested in doing. It’s not the right tool for making finished products, but is intended for creating lab notebooks that contain executable code snippets, formatted text, and visual output together. Given your background experience and the libraries you like, it seems like it’d be right up your alley.




  • Can Z3 account for lost bits? Did it come up with just one solution?

    It gave me just one solution the way I asked for it. With additional constraints added to exclude the original solution, it also gives me a second solution – but the solution it produces is peculiar to my implementation and does not match your implementation. If you implemented exactly how the bits are supposed to end up in the result, you could probably find any other solutions that exist correctly, but I just did it in a quick and dirty way.

    This is (with a little clean up) what my code looked like:

    solver code
    #!/usr/bin/env python3
    
    import z3
    
    rand1 = 0.38203435111790895
    rand2 = 0.5012949781958014
    rand3 = 0.5278898433316499
    rand4 = 0.5114834443666041
    
    def xoshiro128ss(a,b,c,d):
        t = 0xFFFFFFFF & (b << 9)
        r = 0xFFFFFFFF & (b * 5)
        r = 0xFFFFFFFF & ((r << 7 | r >> 25) * 9)
        c = 0xFFFFFFFF & (c ^ a)
        d = 0xFFFFFFFF & (d ^ b)
        b = 0xFFFFFFFF & (b ^ c)
        a = 0xFFFFFFFF & (a ^ d)
        c = 0xFFFFFFFF & (c ^ t)
        d = 0xFFFFFFFF & (d << 11 | d >> 21)
        return r, (a, b, c, d)
    
    a,b,c,d = z3.BitVecs("a b c d", 64)
    nodiv_rand1, state = xoshiro128ss(a,b,c,d)
    nodiv_rand2, state = xoshiro128ss(*state)
    nodiv_rand3, state = xoshiro128ss(*state)
    nodiv_rand4, state = xoshiro128ss(*state)
    
    z3.solve(a >= 0, b >= 0, c >= 0, d >= 0,
      nodiv_rand1 == int(rand1*4294967296),
      nodiv_rand2 == int(rand2*4294967296),
      nodiv_rand3 == int(rand3*4294967296),
      nodiv_rand4 == int(rand4*4294967296)
      )
    
    

    I never heard about Z3

    If you’re not familiar with SMT solvers, they are a useful tool to have in your toolbox. Here are some links that may be of interest:

    Edit: Trying to fix formatting differences between kbin and lemmy
    Edit 2: Spoiler tags and code blocks don’t seem to play well together. I’ve got it mostly working on Lemmy (where I’m guessing most people will see the comment), but I don’t think I can fix it on kbin.


  • If I understand the problem correctly, this is the solution:

    solution

    a = 2299200278
    b = 2929959606
    c = 2585800174
    d = 3584110397

    I solved it with Z3. Took less than a second of computer time, and about an hour of my time – mostly spent trying to remember how the heck to use Z3 and then a little time debugging my initial program.


  • What I’d do is set up a simple website that uses a little JavaScript to rewrite the date and time into the page and periodically refresh an image under/next to it. Size the image to fit the remaining free space of however you set up the iPad, and then you can stick anything you want there (pictures/reminder text/whatever) with your favorite image editor. Upload a new image to the server when you want to change the note. The idea with an image is that it’s just really easy to do and keeps the amount of effort to redo layout to a minimum – just drag stuff around in your image editor and you’ll know it’ll all fit as expected as long as you don’t change the resolution (instead of needing to muck around with CSS and maybe breaking something if you can’t see the device to check that it displays correctly).

    There’s a couple issues to watch out for – e.g. what happens if the internet connection/server goes down, screen burn-in, keeping the browser from being closed/switched to another page, keeping it powered, etc. that might or might not matter depending on your particular circumstances. If you need to fix all that for your circumstances, it might be more trouble than just buying something purpose built… but getting a first pass DIY version working is trivial if you’re comfortable hosting a website.

    Edit: If some sample code that you can use as a starting point would be helpful, let me know.


  • My guess is that if browsers as we know them weren’t invented, HyperCard would’ve become the first browser eventually. No idea where things would progress from there or if it’d have been better or worse than the current clusterfuck. Maybe we’d all be talking about our “web stacks” instead of websites, and have various punny tools like “pile” and “chimney” and “staplr”. Perhaps PowerPoint would’ve turned into a browser to compete with it.

    If browsers were invented but JavaScript specifically was not, we’d probably all be programming sites in some VB variant like VBScript (although it might be called something different).



  • Didn’t the GDPR have a data portability rule requiring that sites provide users the ability to easily export their own data? Does that not apply to Lemmy for some reason – or, am I misremembering it? (I remember account data download being a big deal a while back on reddit, but it’s been a few years…)





  • Any ways to get around the download failing

    I did this incredibly stupid procedure with Firefox yesterday as a workaround for a failing Google Takeout download:

    • backup the .part file from the failed download
    • restart the download (careful – if you didn’t move/back it up, it will be deleted and you will have to download the whole thing again; found this out the hard way on a 50GB+ file… that failed again)
    • immediately pause the new download after it starts writing to disk
    • replace the new .part file with the old .part file from earlier (or – see [1] below)
    • Firefox might not show progress for a long time, but will eventually continue the download (I saw it reading the file back from disk with iotop so I just let it run)
    • sanity check that you actually got the whole thing and that it is usable (in my case, I knew a hash for the file)

    [1] You can actually replace the new .part file with anything that has the same size in bytes as the old file – I replaced it with a file full of zeros and manually merged the end onto the original .part file with a tiny custom python script since I had already moved the incomplete file to other media before realizing I could try this. (In my case, the incomplete file would still have been useful even with the last ~1MB cut off.)

    There are probably better options in most cases – like Thunderbird for mailbox as other people suggested, or rclone for getting stuff from Drive – but if you need to get Takeout to work and the download keeps failing this may be another option to try.




  • It probably makes more sense to host your novel somewhere else and post links to it chapter by chapter.

    I’d suggest doing one of the following:

    1. Host the images on a site that already supports image galleries and link to that. Most image hosts are kind of annoying, but this is an understandable way to do it if you don’t want to run a website. (Maybe someone can chime in with a suggestion for whatever they think is the least annoying image gallery host in 2023.)
    2. Host the images yourself on a simple website. Webcomic artists have been doing that for many years, so there are lots of examples to draw from. (e.g. Gunnerkrigg Court)
    3. Zip the images up chapter by chapter and either self-host the zip or toss it on a file host like catbox.moe. If you structure it as a .cbz (i.e. zip up a folder with the images named in order like 1.jpg, 2.jpg, 3.jpg, … and just change the extension from .zip to .cbz) then a number of document viewers (like evince) can be used to view the image sequence – or people can just unpack the images and use their favorite image viewer on their computer.