fmax, fmaxf, fmaxl

 

C

Language

headers

Type support

Dynamic memory management

Error handling

Program utilities

Variadic function support

Date and time utilities

Strings library

Algorithms

Numerics

Input/output support

Localization support

Thread support (C11)

Atomic operations (C11)

Technical Specifications

 

Numerics

Common mathematical functions

Floating-point environment

Complex number arithmetics

Random number generation

Type-generic math

 

Common mathematical functions

Functions
Basic operations
abslabsllabsimaxabs (C99) fabs divldivlldivimaxdiv (C99) fmod	remainder (C99) remquo (C99) fma (C99) fmax (C99) fmin (C99) fdim (C99) nannanfnanl (C99)(C99)(C99)
Exponential functions
exp exp2 (C99) expm1 (C99)	log log10 log1p (C99) log2 (C99)
Power functions
sqrt cbrt (C99)	hypot (C99) pow
Trigonometric and hyperbolic functions
sin cos tan asin acos atan atan2	sinh cosh tanh asinh (C99) acosh (C99) atanh (C99)
Error and gamma functions
erf (C99) erfc (C99)	lgamma (C99) tgamma (C99)
Nearest integer floating point operations
ceil floor roundlroundllround (C99)(C99)(C99)	trunc (C99) nearbyint (C99) rintlrintllrint (C99)(C99)(C99)
Floating point manipulation functions
ldexp scalbnscalbln (C99)(C99) ilogb (C99) logb (C99)	frexp modf nextafternexttoward (C99)(C99) copysign (C99)
Classification
fpclassify (C99) isfinite (C99) isinf (C99) isnan (C99) isnormal (C99) signbit (C99)	isgreater (C99) isgreaterequal (C99) isless (C99) islessequal (C99) islessgreater (C99) isunordered (C99)
Types
div_tldiv_tlldiv_timaxdiv_t (C99)(C99)	float_tdouble_t (C99)(C99)
Macro constants
HUGE_VALFHUGE_VALHUGE_VALL (C99)(C99) FP_FAST_FMAFFP_FAST_FMAFP_FAST_FMAL (C99)(C99)(C99) math_errhandlingMATH_ERRNOMATH_ERRNOEXCEPT (C99)(C99)(C99)	INFINITY (C99) NAN (C99) FP_ILOGB0FP_ILOGBNAN (C99)(C99) FP_NORMALFP_SUBNORMALFP_ZEROFP_INFINITEFP_NAN (C99)(C99)(C99)(C99)(C99)

 

Defined in header <math.h>
float       fmaxf( float x, float y );	(1)	(since C99)
double      fmax( double x, double y );	(2)	(since C99)
long double fmaxl( long double x, long double y );	(3)	(since C99)
Defined in header <tgmath.h>
#define fmax( x, y )	(4)	(since C99)

1-3) Returns the larger of two floating point arguments, treating NaNs as missing data (between a NaN and a numeric value, the numeric value is chosen).

4) Type-generic macro: If any argument has type long double, fmaxl is called. Otherwise, if any argument has integer type or has type double, fmax is called. Otherwise, fmaxf is called.

Parameters

x, y

-

floating point values

Return value

If successful, returns the larger of two floating point values. The value returned is exact and does not depend on any rounding modes.

Error handling

This function is not subject to any of the error conditions specified in math_errhandling.

If the implementation supports IEEE floating-point arithmetic (IEC 60559),

• If one of the two arguments is NaN, the value of the other argument is returned
• Only if both arguments are NaN, NaN is returned

Notes

This function is not required to be sensitive to the sign of zero, although some implementations additionally enforce that if one argument is +0 and the other is -0, then +0 is returned.

Example

Run this code

#include <stdio.h>
#include <math.h>
 
int main(void)
{
    printf("fmax(2,1)    = %f\n", fmax(2,1));
    printf("fmax(-Inf,0) = %f\n", fmax(-INFINITY,0));
    printf("fmax(NaN,-1) = %f\n", fmax(NAN,-1));
}

Output:

fmax(2,1)    = 2.000000
fmax(-Inf,0) = 0.000000
fmax(NaN,-1) = -1.000000

References

• C11 standard (ISO/IEC 9899:2011):

• 7.12.12.2 The fmax functions (p: 257-258)

• 7.25 Type-generic math <tgmath.h> (p: 373-375)

• F.10.9.2 The fmax functions (p: 530)

• C99 standard (ISO/IEC 9899:1999):

• 7.12.12.2 The fmax functions (p: 238-239)

• 7.22 Type-generic math <tgmath.h> (p: 335-337)

• F.9.9.2 The fmax functions (p: 466)

See also

isgreater (C99)	checks if the first floating-point argument is greater than the second (function)
fminfminffminl (C99)(C99)(C99)	determines smaller of two floating-point values (function)
C++ documentation for fmax