[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

single-float-epsilon



Sorry I didn't notice this before, but I'm not sure that the definition
of single-float-epsilon given in the manual is really what you intended.
Specifically, on most machines (those that do rounding to nearest) this
number is -not- a power of 2, rather it is one unit in the least significant
place more than a power of 2.  I would think that most applications of
this would prefer to have a power of 2.

Is it possible that the definition you wanted was "the largest positive
floating-point number e such that the expression
	(= (float 1 e) (+ (float 1 e) e))
is false when actually evaluated."?

In the meantime I've fixed our implementation to conform to the manual
instead of having a value that was off by a hair less than a power of 2
(the person computing the value clearly must have assumed that it was
meant to be a power of 2 and didn't consider other numbers).