- fplog2 xprocedure
- x
- flonum
Computes the base-2 log of x more accurately than (/ (fplog x) (fplog 2.0)). In particular, (fplog2 x) is correct for any power of two x.
Examples:
> (fplog2 4.5) 2.169925001442312 > (/ (fplog (fpexp2 -1066.0)) (fplog 2.0)) -1066.0000000000002 > (fplog2 (fpexp2 -1066.0)) -1066.0
Maximum observed error is 0.5006 ulps (see fpulp), but is almost always no more than 0.5 (i.e. it is almost always correct).