Wednesday 5 July 2023

Sweet Mystery

 This packet contains 12 sweets of 4 different colours (black, red, yellow and - my favourites - green). 


The number and order of the colours in each pack appears to be random (based on many, many samples 😉 ). If my calculations are correct and if they are really randomly distributed, one in every 4.2 million packets will contain 12 sweets of the same colour. Something I have often wondered about: how do the manufacturers avoid this? I can see a number of possibilities:  
  • Don't worry about it - it happens infrequently enough not to care
  • Optically scan each group of 12 sweets just before wrapping them and if they aren't sufficiently heterogeneous, don't wrap them - throw them back into the pot and try again. This only seems like it would be worth doing if they were optically scanning them anyway for other reasons (e.g. quality control)
  • They don't really throw all of the colours into one big pot and select them at random: they keep the individual colours separate right up to the packing stage and just shuffle the order in which they pick them to create the appearance of randomness.
Does anyone have any theories or insights? I'd love to know. In the meantime I'll keep eating them - purely in the interests of science, of course 🙂

Saturday 3 June 2023

GIMP Start-up Hang

This was a pain-in-the-ass to troubleshoot, so I'm sharing the story here in the hope that it will help someone else.

I have GIMP installed on a Windows 10 machine. Out of the blue, it started hanging on start-up: the main window would appear, but then it would freeze for about 5 minutes. Uninstalling and reinstalling didn't help and no amount of Googling yielded any solution.

The first useful clue I got was after it did become responsive (finally, after the 5-minute delay) and I clicked on the "File" menu-item, causing it to hang again for another 5 minutes. That hinted that the problem was with the "Recently Used" file list.  So where does GIMP store the list of recently-used files? Nowhere obvious, it turns out: on Windows, GIMP stores its recently-used file list in C:\Users\%USERNAME%\appdata\Local\recently-used.xbel (which may be shared by other applications).  It is an XML-format file.  Sure enough, in there are a bunch of references to files on a network share that no longer exists:-

Contents of recently-used.xbel file, showing references to non-existent network share

I could probably have just deleted the entire file, but it was sufficient to just delete the <bookmark>...</bookmark> sections that referenced the now-absent network share.

I have to give a hat-tip Bing for leading me to the solution.  None of my Google searches along the lines of "where does gimp store its recently used file list" yielded any useful hints about where to look.  I was just about to start reading through the GIMP source-code - a daunting prospect - when I decided to try the same search on Bing:-

Bing search result referencing recently-used.xbel

Even though this result refers to GIMP running on Linux, it was enough: one quick search for a file called "recently-used.xbel" and I was away. And so the score stands at Bing 1, Google 0.