NAME

intro − introduction to the math library

SYNOPSIS

cc [flag ...] file ... −lm [library ...]

#include <math.h>

DESCRIPTION

This section describes the functions in the math library, libm. Declarations for these functions may be obtained from the #include file math.h. Several generally useful mathematical constants are also defined there [see intro(3) and math(5)]. 

The reference manual pages are divided as follows:

• Commands Reference Manual, Volumes 1: Section 1 and all Section 1 subsections, and Section 5 manual pages related to commands. 

• System Calls and Library Functions Reference Manual: Sections 2, 3, and all Section 3 subsections, and Section 5 manual pages related to programming. 

• System Files and Devices Reference Manual: Sections 4 and 7. 

The math library is not automatically loaded by the C compilation system; use the −l option to cc to access the library as follows:

−lm Search the regular math library, libm.

libm contains the full set of double-precision routines plus some single-precision routines (designated by the suffix f) that may give better performance with less precision. 

DEFINITIONS

See intro(3) for C language definitions. 

FILES

LIBDIR usually /usr/ccs/lib

LIBDIR/libm.a

SEE ALSO

cc(1), intro(2), intro(3), math(5)

DIAGNOSTICS

Error handling varies according to compilation mode.  Under the −Xt (default) option to cc, these functions return the conventional values 0, ±HUGE, or NaN when the function is undefined for the given arguments or when the value is not representable.  In the −Xa and −Xc compilation modes, ±HUGE_VAL is returned instead of ±HUGE.  (HUGE_VAL and HUGE are defined in math.h to be infinity and the largest-magnitude single-precision number, respectively.)  In every case, the external variable errno [see intro(2)] is set to the value EDOM or ERANGE, although the value may vary for a given error depending on compilation mode.  See the table under matherr(3M) below. 

  —  Math Libraries