Re: Maybe I'm just dumb...

[Evanovich]

Folks. I figured out the problem, but I can't figure out why it would give me an error. If I don't take the acos of $d, and just multiply (180/3.14159)*$d, then I can sort normally. Can anyone explain to me why the acos() function would be screwing up my sort?

[Enlil]

Try this:

use Math::Cephes qw/acos/;
for ( -2, -1.1, -1, 0, 1, 1.1, 2 ) {
  print acos($_),$/;
}

I expect you are getting something similar (i.e. #QNAN), as I am guessing some of the values $d are outside the domain of the "Real" solutions of acos.

-enlil

[belg4mit]

Can't acos return undef (for invalid input)?

--
I'm not belgian but I play one on TV.

[SparkeyG]

Just a thought, but is $dotproduct a PDL? If so, using acos should screw things up. But it's been a while since I used PDL.