math -- introduction to mathematical library functions

These functions constitute the C math library, libm. The link editor searches this library under the -lm option. Declarations for these functions may be obtained from the include file <math.h>.

Please consult <fenv.h>, <complex.h>, and <tgmath.h> for other math components.

LIST OF FUNCTIONS

Algebraic Functions

Name	Description
`cbrt()`	cube root
`fma()`	fused multiply-add
`hypot()`	Euclidean distance
`sqrt()`	square root

Classification Macros

Name	Description
`fpclassify()`	classify a floating-point value
`isfinite()`	determine whether a value is finite
`isinf()`	determine whether a value is infinite
`isnan()`	determine whether a value is NaN
`isnormal()`	determine whether a value is normalized

Exponent Manipulation Functions

Name	Description
`frexp()`	extract exponent and mantissa
`ilogb()`	extract exponent
`ldexp()`	multiply by power of 2
`logb()`	extract exponent
`scalbln()`	adjust exponent
`scalbn()`	adjust exponent

Extremum- and Sign-Related Functions

Name	Description
`copysign()`	copy sign bit
`fabs()`	absolute value
`fdim()`	positive difference
`fmax()`	maximum function
`fmin()`	minimum function
`signbit()`	extract sign bit

Not a Number Functions

Name	Description
`nan()`	generate a quiet NaN

Residue and Rounding Functions

Name	Description
`ceil()`	integer no less than
`floor()`	integer no greater than
`fmod()`	positive remainder
`llrint()`	round to integer in fixed-point format
`llround()`	round to nearest integer in fixed-point format
`lrint()`	round to integer in fixed-point format
`lround()`	round to nearest integer in fixed-point format
`modf()`	extract integer and fractional parts
`nearbyint()`	round to integer (silent)
`nextafter()`	next representable value
`nexttoward()`	next representable value
`remainder()`	remainder
`remquo()`	remainder with partial quotient
`rint()`	round to integer
`round()`	round to nearest integer
`trunc()`	integer no greater in magnitude than

The ceil(), floor(), llround(), lround(), round(), and trunc() functions round in predetermined directions, whereas llrint(), lrint(), and rint() round according to the current (dynamic) rounding mode. For more information on controlling the dynamic rounding mode, see fenv() and fesetround().

Silent Order Predicates

Name	Description
`isgreater()`	greater than relation
`isgreaterequal()`	greater than or equal to relation
`isless()`	less than relation
`islessequal()`	less than or equal to relation
`islessgreater()`	less than or greater than relation
`isunordered()`	unordered relation

Transcendental Functions

Name	Description
`acos()`	inverse trigonometric function
`acosh()`	inverse hyperbolic function
`asin()`	inverse trigonometric function
`asinh()`	inverse hyperbolic function
`atan()`	inverse trigonometric function
`atanh()`	inverse hyperbolic function
`atan2()`	inverse trigonometric function
`cos()`	trigonometric function
`cosh()`	hyperbolic function
`erf()`	error function
`erfc()`	complementary error function
`exp()`	base e exponential
`exp2()`	base 2 exponential
`expm1()`	exp(x)-1
`j0()`	bessel function
`j1()`	bessel function
`jn()`	bessel function
`lgamma()`	log gamma function
`log()`	natural logarithm
`log2()`	logarithm to base 2
`log10()`	logarithm to base 10
`log1p()`	log(1+x)
`sin()`	trigonometric function
`sinh()`	hyperbolic function
`tan()`	trigonometric function
`tanh()`	hyperbolic function
`y0()`	bessel function
`y1()`	bessel function
`yn()`	bessel function

The routines in this section might not produce a result that is correctly rounded, so reproducible results cannot be guaranteed across platforms. For most of these functions, however, incorrect rounding occurs rarely, and then only in very-close-to-halfway cases.

NOTES

The math library can handle floating point exceptions in different ways depending upon the level of standards conformance that the user desires. The math library currently supports the following personality modes:

__XOPEN__
__POSIX__
__SVID__
__IEEE__

For details on these personality modes, see the _NutLibMSetLibraryType() reference page.

By default, floating-point exeptions are masked in processor hardware. It enable/disable/query exceptions, use fenv() functions feenableexcept (), fedisableexcept(), and fegetexcept(). Hardware exceptions will then be converted to signals and may be trapped by SIGFPE handers.

CONFORMANCE

ANSI/ISO 9899:1999 'ISO C99'.

AVAILABILITY

PTC MKS Toolkit for Professional Developers
PTC MKS Toolkit for Professional Developers 64-Bit Edition
PTC MKS Toolkit for Enterprise Developers
PTC MKS Toolkit for Enterprise Developers 64-Bit Edition

math
introduction to mathematical library functions

Function Summary

SYNOPSIS

DESCRIPTION