cc [ flags ] -I/usr/local/include file(s) -L/usr/local/lib -lmcw [ ... ] #include <mathcw.h> extern float log2f (float x); extern double log2 (double x); extern long double log2l (long double x); extern __float80 log2w (__float80 x); extern __float128 log2q (__float128 x); extern long_long_double log2ll (long_long_double x); extern decimal_float log2df (decimal_float x); extern decimal_double log2d (decimal_double x); extern decimal_long_double log2dl (decimal_long_double x); extern decimal_long_long_double log2dll (decimal_long_long_double x);
NB: Functions with prototypes containing underscores in type names may be available only with certain extended compilers.
Caution: Avoid use of log2(1 + x) for small-magnitude x; use log21p(x) instead to avoid serious accuracy loss.