On Tue, Aug 2, 2016 at 11:45 AM, Random832 <random832@fastmail.com> wrote:
Sure, but what the standard doesn't say is exactly what sequence of comparisons is entailed by a clamp function.
def clamp(x, a, b): if x < a: return a else: if x > b: return b else: return x
def clamp(x, a, b): if a <= x: if x <= b: return x else: return b else: return a
There are, technically, eight possible naive implementations, varying along three axes:
Exactly-- I thought this was self evident, but apparently not -- thanks for spelling it out.
All such functions are equivalent if {a, b, x} is a set over which the relational operators define a total ordering, and a <= b. However, this is not the case if NaN is used for any of the arguments.
Exactly again -- NaN's are kind of a pain :-( As for the convert to floats issue -- correctness is more important than performance, and performance is probably most important for the special case of all floats. (or floats and integers, I suppose) -- i'm sure we can find a solution. LIkely something iike the second option above would work fine, and also work for anything with an ordinary total ordering. -Chris -- Christopher Barker, Ph.D. Oceanographer Emergency Response Division NOAA/NOS/OR&R (206) 526-6959 voice 7600 Sand Point Way NE (206) 526-6329 fax Seattle, WA 98115 (206) 526-6317 main reception Chris.Barker@noaa.gov