As seen/discussed on one of the several R mailing lists:

R version 4.4.1 (2024-06-14 ucrt) -- "Race for Your Life"
Copyright (C) 2024 The R Foundation for Statistical Computing
[...]

> atan(1i)
[1] 0+Infi
> atan(1i)*2
[1] NaN+Infi

Oops. The reason for this is that apparently, when multiplying (or dividing) a complex number by a real number ( Read more... )

Finally had some time to do a bit more cosmetic work on the Song of Ice and Fire RP test probability report generator script again - tables are colorized now, and the whole document produced is a nicely (well, reasonably so) organized book now, with a title page and PDF bookmarks and using a fairly pleasant font, Libertinus Serif.

Here's a sample ( Read more... )

I'll join a Song of Ice and Fire RPG campaign soon. The system - by Green Ronin - uses a d6-based roll-and-keep mechanism for tests; the procedure for a regular test for a certain ability is

1. to roll N dice, where N is equal to your ability score;
   
2. to roll K bonus dice (if any), resulting from specialties or from assistance received;
3. discard the ( Read more... )

Just to drive home again the point that floating point arithmetic is evil, try running the following in MATLAB:

>> 0.2+0.1==0.3

ans =

logical

0

>>

What's happening? As you likely guessed, floating point arithmetic is to blame; adding the numbers 0.2 and 0.1 doesn't make 0.3, in the sense that the floating-point representations of ( Read more... )

Quick note on upgrading R while keeping your packages - the following recipe, suggested over on R-bloggers, works flawlessly for me, and for the sake of preserving it (and for my own reference so I can find it again easily) I'm reproducing it here, while also adding some comments and indicating how to do this using RStudio.

1. 
   
   Using the old ( Read more... )

Whatever happened to the notion that error messages are intended for users, and should help users diagnosing and ideally fixing the problem that caused the error?

Take keras, for instance, a package for training neural networks that's also available in R. Running code along the following lines

# ...

network <- keras_model_sequential( ( Read more... )

It's a breeze, using qpdf:

$ qpdf --verbose --decrypt --password=PASSWORD encrypted_file.pdf decrypted_file.pdf
qpdf: wrote file decrypted_file.pdf
$

To decrypt several files at once, you can use your shell's facilities:

$ for i in *.pdf; do qpdf --verbose --decrypt --password=PASSWORD ${i} ${i/.pdf/_decrypted.pdf} ; done ( Read more... )

So, official Flash support from Macromedia Adobe is finally coming to an end. And this doesn't just mean there won't be any updates, it also means that all existing Flash installations will work. Gotta love built-in kill switches ( Read more... )

Pro tip: if you're using TeXstudio and SumatraPDF - which you probably are, since TeXstudio is the best TeX environment by far, and SumatraPDF is the best PDF reader -, you may be happy to learn that SumatraPDF actually supports synctex files; simply go to Settings > Options, and set the ,,inverse search command line`` to something along the ( Read more... )

BTW, if you find yourself wondering why Firefox (on Android) is taking up a huge amount of system space (a gigabyte, say) even after you clear all browser data, cache etc. …

… then I can't tell you why, but I can tell you that removing and reinstalling it will help - though you should jot down your settings, extensions, bookmarks etc. first, since ( Read more... )