/C

# fmax, fmaxf, fmaxl

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

```#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)

 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`