Jump to page content

Bug of the moment 2007-05-08

This entry is for Katherine Elliott, if she is reading this somewhere out there.

Microsoft, dear Microsoft …

BetBest1 (of Crtl fame) has introduced me to another delight of Microsoft’s: PowerToy Calc (or “Powertoy”, since their shift key seems stuck at times). He gave me the download link for it which, although it was for XP only, I thought I’d try it anyway. Apparently, backwards compatibility in Vista isn’t so great, but surely I have enough service packs to satisfy its needs?

powertoys will not function on a version of Windows earlier or later than Windows XP

Either that, or Vista has a math-that-works daemon that prevents execution of code for which sin of 8000 radians causes the program to hang:

Surely you would normalise the argument to sin to be within range (0 to ± 360 / 2π / 400 depending) but no, PowerToy Calc (which, curiously, has the same icon as regular Calculator) would rather trundle all the way down to 8000 gathering inaccuracies along the way. For example, sin 8000°:

sin(8000°) = approximately 3 billion trillion

How about sin 400 rad:

sin(400 rad) = 1.34E134

(I received these two screenshots from BetBest1 last night, which might explain my uncomfortable dream this morning about one of my sixth form maths teachers)

You can see the problem starting to creep in here:

Well, not so much creeping as a runaway train of overflow.

(For those who didn’t pick up on the subtle clues: yes, I used the family XP computer to play with the program and take some extra screenshots. I didn’t hack PowerToy Calc to run on my own Windows 2000 computer.)

Posted 8th May 2007 – Comments and questions?