<math.h>
abs
· acos
· asin
· atan
· atan2
· ceil
· cos
· cosh
· exp
· fabs
· floor
· fmod
· frexp
· ldexp
· log
· log10
· modf
· pow
· sin
· sinh
· sqrt
· tan
· tanh
acosf
· asinf
· atanf
· atan2f
· ceilf
· cosf
· coshf
· expf
· fabsf
· floorf
· fmodf
· frexpf
· ldexpf
· logf
· log10f
· modff
· pow
· sinf
· sinhf
· sqrtf
· tanf
· tanhf
acosl
· asinl
· atanl
· atan2l
· ceill
· cosl
· coshl
· expl
· fabsl
· floorl
· fmodl
· frexpl
· ldexpl
· logl
· log10l
· modfl
· pow
· sinl
· sinhl
· sqrtl
· tanl
· tanhl
Include the standard header <math.h>
to declare a number of functions that perform
common mathematical operations on real floating-point values
(of type float, double, or long double).
A domain error
occurs when the function is
not defined for its input argument value or values. A function can report
a domain error by storing the value of
EDOM
in
errno
and returning a particular value defined for each implementation.
A range error
occurs when the return value of the
function is defined but cannot be represented.
A function can report a range error by storing the value of
ERANGE
in
errno
and returning one of several values:
HUGE_VAL
-- if the value of a function returning double is positive
and too large in magnitude to represent-HUGE_VAL
-- if the value of a function returning double is negative
and too large in magnitude to represent/* MACROS */ #define HUGE_VAL <double rvalue> /* FUNCTIONS */ double abs(double x); [C++ only] float abs(float x); [C++ only] long double abs(long double x); [C++ only] double acos(double x); float acos(float x); [C++ only] long double acos(long double x); [C++ only] float acosf(float x); [required with C99] long double acosl(long double x); [required with C99] double asin(double x); float asin(float x); [C++ only] long double asin(long double x); [C++ only] float asinf(float x); [required with C99] long double asinl(long double x); [required with C99] double atan(double x); float atan(float x); [C++ only] long double atan(long double x); [C++ only] float atanf(float x); [required with C99] long double atanl(long double x); [required with C99] double atan2(double y, double x); float atan2(float y, float x); [C++ only] long double atan2(long double y, long double x); [C++ only] float atan2f(float y, float x); [required with C99] long double atan2l(long double y, long double x); [required with C99] double ceil(double x); float ceil(float x); [C++ only] long double ceil(long double x); [C++ only] float ceilf(float x); [required with C99] long double ceill(long double x); [required with C99] double cos(double x); float cos(float x); [C++ only] long double cos(long double x); [C++ only] float cosf(float x); [required with C99] long double cosl(long double x); [required with C99] double cosh(double x); float cosh(float x); [C++ only] long double cosh(long double x); [C++ only] float coshf(float x); [required with C99] long double coshl(long double x); [required with C99] double exp(double x); float exp(float x); [C++ only] long double exp(long double x); [C++ only] float expf(float x); [required with C99] long double expl(long double x); [required with C99] double fabs(double x); float fabs(float x); [C++ only] long double fabs(long double x); [C++ only] float fabsf(float x); [required with C99] long double fabsl(long double x); [required with C99] double floor(double x); float floor(float x); [C++ only] long double floor(long double x); [C++ only] float floorf(float x); [required with C99] long double floorl(long double x); [required with C99] double fmod(double x, double y); float fmod(float x, float y); [C++ only] long double fmod(long double x, long double y); [C++ only] float fmodf(float x, float y); [required with C99] long double fmodl(long double x, long double y); [required with C99] double frexp(double x, int *pexp); float frexp(float x, int *pexp); [C++ only] long double frexp(long double x, int *pexp); [C++ only] float frexpf(float x, int *pexp); [required with C99] long double frexpl(long double x, int *pexp); [required with C99] double ldexp(double x, int ex); float ldexp(float x, int ex); [C++ only] long double ldexp(long double x, int ex); [C++ only] float ldexpf(float x, int ex); [required with C99] long double ldexpl(long double x, int ex); [required with C99] double log(double x); float log(float x); [C++ only] long double log(long double x); [C++ only] float logf(float x); [required with C99] long double logl(long double x); [required with C99] double log10(double x); float log10(float x); [C++ only] long double log10(long double x); [C++ only] float log10f(float x); [required with C99] long double log10l(long double x); [required with C99] double modf(double x, double *pint); float modf(float x, float *pint); [C++ only] long double modf(long double x, long double *pint); [C++ only] float modff(float x, float *pint); [required with C99] long double modfl(long double x, long double *pint); [required with C99] double pow(double x, double y); float pow(float x, float y); [C++ only] long double pow(long double x, long double y); [C++ only] double pow(double x, int y); [C++ only] float pow(float x, int y); [C++ only] long double pow(long double x, int y); [C++ only] float powf(float x, float y); [required with C99] long double powl(long double x, long double y); [required with C99] double sin(double x); float sin(float x); [C++ only] long double sin(long double x); [C++ only] float sinf(float x); [required with C99] long double sinl(long double x); [required with C99] double sinh(double x); float sinh(float x); [C++ only] long double sinh(long double x); [C++ only] float sinhf(float x); [required with C99] long double sinhl(long double x); [required with C99] double sqrt(double x); float sqrt(float x); [C++ only] long double sqrt(long double x); [C++ only] float sqrtf(float x); [required with C99] long double sqrtl(long double x); [required with C99] double tan(double x); float tan(float x); [C++ only] long double tan(long double x); [C++ only] float tanf(float x); [required with C99] long double tanl(long double x); [required with C99] double tanh(double x); float tanh(float x); [C++ only] long double tanh(long double x); [C++ only] float tanhf(float x); [required with C99] long double tanhl(long double x); [required with C99]
abs
,
fabs
,
fabsf
,
fabsl
double abs(double x); [C++ only] float abs(float x); [C++ only] long double abs(long double x); [C++ only] double fabs(double x); float fabs(float x); [C++ only] long double fabs(long double x); [C++ only] float fabsf(float x); [required with C99] long double fabsl(long double x); [required with C99]
The function returns the magnitude of x
,
|x|
.
acos
,
acosf
,
acosl
double acos(double x); float acos(float x); [C++ only] long double acos(long double x); [C++ only] float acosf(float x); [required with C99] long double acosl(long double x); [required with C99]
The function returns the angle whose cosine is x
, in
the range [0, pi] radians. A domain error occurs if 1 < |x|
.
asin
,
asinf
,
asinl
double asin(double x); float asin(float x); [C++ only] long double asin(long double x); [C++ only] float asinf(float x); [required with C99] long double asinl(long double x); [required with C99]
The function returns the angle whose sine is x
, in the
range [-pi/2, +pi/2] radians. A domain error occurs
if 1 < |x|
.
atan
,
atanf
,
atanl
double atan(double x); float atan(float x); [C++ only] long double atan(long double x); [C++ only] float atanf(float x); [required with C99] long double atanl(long double x); [required with C99]
The function returns the angle whose tangent is x
, in
the range [-pi/2, +pi/2] radians.
atan2
,
atan2f
,
atan2l
double atan2(double y, double x); float atan2(float y, float x); [C++ only] long double atan2(long double y, long double x); [C++ only] float atan2f(float y, float x); [required with C99] long double atan2l(long double y, long double x); [required with C99]
The function returns the angle whose tangent is y/x
,
in the full angular range [-pi, +pi] radians. A domain error may occur
if both x
and y
are zero.
ceil
,
ceilf
,
ceill
double ceil(double x); float ceil(float x); [C++ only] long double ceil(long double x); [C++ only] float ceilf(float x); [required with C99] long double ceill(long double x); [required with C99]
The function returns the smallest integer value not less than
x
.
cos
,
cosf
,
cosl
double cos(double x); float cos(float x); [C++ only] long double cos(long double x); [C++ only] float cosf(float x); [required with C99] long double cosl(long double x); [required with C99]
The function returns the cosine of x
.
If x
is large the value returned
might not be meaningful, but the function reports no error.
cosh
,
coshf
,
coshl
double cosh(double x); float cosh(float x); [C++ only] long double cosh(long double x); [C++ only] float coshf(float x); [required with C99] long double coshl(long double x); [required with C99]
The function returns the hyperbolic cosine of x
.
exp
,
expf
,
expl
double exp(double x); float exp(float x); [C++ only] long double exp(long double x); [C++ only] float expf(float x); [required with C99] long double expl(long double x); [required with C99]
The function returns the exponential of x
,
e^x
.
floor
,
floorf
,
floorl
double floor(double x); float floor(float x); [C++ only] long double floor(long double x); [C++ only] float floorf(float x); [required with C99] long double floorl(long double x); [required with C99]
The function returns the largest integer value not greater than
x
.
fmod
,
fmodf
,
fmodl
double fmod(double x, double y); float fmod(float x, float y); [C++ only] long double fmod(long double x, long double y); [C++ only] float fmodf(float x, float y); [required with C99] long double fmodl(long double x, long double y); [required with C99]
The function returns the remainder of x/y
,
which is defined as follows:
y
is zero,
the function either reports a domain error or simply returns zero.i
such that the returned value x - i * y
has the
same sign as x
and magnitude less than |y|
.frexp
,
frexpf
,
frexpl
double frexp(double x, int *pexp); float frexp(float x, int *pexp); [C++ only] long double frexp(long double x, int *pexp); [C++ only] float frexpf(float x, int *pexp); [required with C99] long double frexpl(long double x, int *pexp); [required with C99]
The function determines a fraction frac
and an exponent integer
ex
that represent the value of x
.
It returns the value frac
and stores the integer
ex
in *pexp
, such that:
|frac|
is in the interval [1/2, 1) or is zerox == frac * 2^ex
If x
is zero, *pexp
is also zero.
HUGE_VAL
#define HUGE_VAL <double rvalue>
The macro yields the double value returned by some functions on a range error. The value can be a representation of infinity.
ldexp
,
ldexpf
,
ldexpl
double ldexp(double x, int ex); float ldexp(float x, int ex); [C++ only] long double ldexp(long double x, int ex); [C++ only] float ldexpf(float x, int ex); [required with C99] long double ldexpl(long double x, int ex); [required with C99]
The function returns x * 2^ex
.
log
,
logf
,
logl
double log(double x); float log(float x); [C++ only] long double log(long double x); [C++ only] float logf(float x); [required with C99] long double logl(long double x); [required with C99]
The function returns the natural logarithm of x
.
A domain error occurs if x < 0
.
log10
,
log10f
,
log10l
double log10(double x); float log10(float x); [C++ only] long double log10(long double x); [C++ only] float log10f(float x); [required with C99] long double log10l(long double x); [required with C99]
The function returns the base-10 logarithm of x
.
A domain error occurs if x < 0
.
modf
,
modff
,
modfl
double modf(double x, double *pint); float modf(float x, float *pint); [C++ only] long double modf(long double x, long double *pint); [C++ only] float modff(float x, float *pint); [required with C99] long double modfl(long double x, long double *pint); [required with C99]
The function determines an integer i
plus a fraction
frac
that represent the value of x
.
It returns the value frac
and stores the integer
i
in *pint
, such that:
x == frac + i
|frac|
is in the interval [0, 1)frac
and i
have the
same sign as x
pow
,
powf
,
powl
double pow(double x, double y); float pow(float x, float y); [C++ only] long double pow(long double x, long double y); [C++ only] double pow(double x, int y); [C++ only] float pow(float x, int y); [C++ only] long double pow(long double x, int y); [C++ only] float powf(float x, float y); [required with C99] long double powl(long double x, long double y); [required with C99]
The function returns x
raised to the power y
,
x^y
.
sin
,
sinf
,
sinl
double sin(double x); float sin(float x); [C++ only] long double sin(long double x); [C++ only] float sinf(float x); [required with C99] long double sinl(long double x); [required with C99]
The function returns the sine of x
.
If x
is large
the value returned might not be meaningful, but
the function reports no error.
sinh
,
sinhf
,
sinhl
double sinh(double x); float sinh(float x); [C++ only] long double sinh(long double x); [C++ only] float sinhf(float x); [required with C99] long double sinhl(long double x); [required with C99]
The function returns the hyperbolic sine of x
.
sqrt
,
sqrtf
,
sqrtl
double sqrt(double x); float sqrt(float x); [C++ only] long double sqrt(long double x); [C++ only] float sqrtf(float x); [required with C99] long double sqrtl(long double x); [required with C99]
The function returns the real square root of x
,
x^(1/2)
. A domain error occurs if x < 0
.
tan
,
tanf
,
tanl
double tan(double x); float tan(float x); [C++ only] long double tan(long double x); [C++ only] float tanf(float x); [required with C99] long double tanl(long double x); [required with C99]
The function returns the tangent of x
.
If x
is large the value returned
might not be meaningful,
but the function reports no error.
tanh
,
tanhf
,
tanhl
double tanh(double x); float tanh(float x); [C++ only] long double tanh(long double x); [C++ only] float tanhf(float x); [required with C99] long double tanhl(long double x); [required with C99]
The function returns the hyperbolic tangent of x
.
See also the Table of Contents and the Index.
Copyright © 1989-2002 by P.J. Plauger and Jim Brodie. All rights reserved.