std::fmax

 

C++

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Technical Specifications

 

Numerics library

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Floating-point environment

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Compile-time rational arithmetic (C++11)

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iota (C++11)

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Common mathematical functions

Functions
Basic operations
abs(int)labsllabsimaxabs (C++11) abs(float)fabs divldivlldivimaxdiv (C++11) fmod	remainder (C++11) remquo (C++11) fma (C++11) fmax (C++11) fmin (C++11) fdim (C++11) nannanfnanl (C++11)(C++11)(C++11)
Exponential functions
exp exp2 (C++11) expm1 (C++11)	log log10 log1p (C++11) log2 (C++11)
Power functions
sqrt cbrt (C++11)	hypot (C++11) pow
Trigonometric and hyperbolic functions
sin cos tan asin acos atan atan2	sinh cosh tanh asinh (C++11) acosh (C++11) atanh (C++11)

Error and gamma functions
erf (C++11) erfc (C++11)	lgamma (C++11) tgamma (C++11)
Nearest integer floating point operations
ceil floor roundlroundllround (C++11)(C++11)(C++11)	trunc (C++11) nearbyint (C++11) rintlrintllrint (C++11)(C++11)(C++11)
Floating point manipulation functions
ldexp scalbnscalbln (C++11)(C++11) ilogb (C++11) logb (C++11)	frexp modf nextafternexttoward (C++11)(C++11) copysign (C++11)
Classification/Comparison
fpclassify (C++11) isfinite (C++11) isinf (C++11) isnan (C++11) isnormal (C++11) signbit (C++11)	isgreater (C++11) isgreaterequal (C++11) isless (C++11) islessequal (C++11) islessgreater (C++11) isunordered (C++11)
Macro constants
HUGE_VALFHUGE_VALHUGE_VALL (C++11)(C++11) INFINITY (C++11) NAN (C++11) math_errhandlingMATH_ERRNOMATH_ERREXCEPT (C++11)	FP_NORMALFP_SUBNORMALFP_ZEROFP_INFINITEFP_NAN (C++11)(C++11)(C++11)(C++11)(C++11)

 

Defined in header <cmath>
float       fmax( float x, float y );	(1)	(since C++11)
double      fmax( double x, double y );	(2)	(since C++11)
long double fmax( long double x, long double y );	(3)	(since C++11)
Promoted    fmax( Arithmetic1 x, Arithmetic2 y );	(4)	(since C++11)

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) A set of overloads or a function template for all combinations of arguments of arithmetic type not covered by 1-3). If any argument has integral type, it is cast to double. If any other argument is long double, then the return type is long double, otherwise it is double.

Parameters

x, y

-

values of floating-point or integral types

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 <iostream>
#include <cmath>
 
int main()
{
    std::cout << "fmax(2,1)    = " << std::fmax(2,1) << '\n'
              << "fmax(-Inf,0) = " << std::fmax(-INFINITY,0) << '\n'
              << "fmax(NaN,-1) = " << std::fmax(NAN,-1) << '\n';
}

Output:

fmax(2,1)    = 2
fmax(-Inf,0) = 0
fmax(NaN,-1) = -1

See also

isgreater (C++11)	checks if the first floating-point argument is greater than the second (function)
fmin (C++11)	smaller of two floating point values (function)
max	returns the larger of two elements (function template)
max_element	returns the largest element in a range (function template)
minmax (C++11)	returns the larger and the smaller of two elements (function template)
minmax_element (C++11)	returns the smallest and the largest element in a range (function template)
C documentation for fmax