# [PD] countings

Mathieu Bouchard matju at sympatico.ca
Thu Jul 10 20:53:44 CEST 2003

```On Thu, 10 Jul 2003, Edward George wrote:

> Maybe I'm just being pedantic:) (but it is the morning and I can't
> deal with anything more complex) but 360degrees is equal to 0 degrees
> so you'd want to go from 359 to 0 or 360 to 1.

You're not being pedantic, you're being wrong, and I'm the real pedantic
this morning ;-)

If you want to make a full circle but so that the circle function is a
bijection from a real segment onto a circle, then you need a half-open
interval of length exactly 2*PI radians, or 360 degrees.

So 0 to 360 degrees, with either of the bounds excluded, is a proper
interval for that. If, for example, we pick the one that excludes the 360
bound, the set has theoretically no maximum, but in the float32
approximation, 359.99997 is the maximum, as it is 360*(1-2^-24).

Have a good day :-)

________________________________________________________________
Mathieu Bouchard                       http://artengine.ca/matju

```