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log2 (3)

LOG2(3) Linux Programmer's Manual LOG2(3) NAME log2, log2f, log2l - base-2 logarithmic function SYNOPSIS #include <math.h> double log2(double x); float log2f(float x); long double log2l(long double x); Link with -lm. Feature Test Macro Requirements for glibc (see feature_test_macros(7)): log2(), log2f(), log2l(): _XOPEN_SOURCE >= 600 || _ISOC99_SOURCE; or cc -std=c99 DESCRIPTION The log2() function returns the base 2 logarithm of x. ERRORS The log2() function can return the following error: EDOM The argument x is negative. ERANGE The argument x is zero. The log of zero is not defined (minus infinity). CONFORMING TO SVr4, 4.3BSD, C89. The float and long double variants are C99 require- ments. SEE ALSO cbrt(3), clog2(3), sqrt(3) 2007-07-26 LOG2(3)