function
<cmath> <ctgmath>
nearbyint
double nearbyint (double x); float nearbyintf (float x);long double nearbyintl (long double x);
double nearbyint (double x); float nearbyint (float x);long double nearbyint (long double x); double nearbyint (T x); // additional overloads for integral types
Round to nearby integral value
Rounds x to an integral value, using the rounding direction specified by fegetround.
This function does not raise FE_INEXACT exceptions. See rint for an equivalent function that may do.
Header
<tgmath.h> provides a type-generic macro version of this function.
Additional overloads are provided in this header (
<cmath>) for the
integral types: These overloads effectively cast
x to a
double before calculations (defined for
T being any
integral type).
Parameters
- x
- Value to round.
Return Value
The value of x rounded to a nearby integral (as a floating-point value).
Example
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/* nearbyint example */
#include <stdio.h> /* printf */
#include <fenv.h> /* fegetround, FE_* */
#include <math.h> /* nearbyint */
int main ()
{
printf ("rounding using ");
switch (fegetround()) {
case FE_DOWNWARD: printf ("downward"); break;
case FE_TONEAREST: printf ("to-nearest"); break;
case FE_TOWARDZERO: printf ("toward-zero"); break;
case FE_UPWARD: printf ("upward"); break;
default: printf ("unknown");
}
printf (" rounding:\n");
printf ( "nearbyint (2.3) = %.1f\n", nearbyint(2.3) );
printf ( "nearbyint (3.8) = %.1f\n", nearbyint(3.8) );
printf ( "nearbyint (-2.3) = %.1f\n", nearbyint(-2.3) );
printf ( "nearbyint (-3.8) = %.1f\n", nearbyint(-3.8) );
return 0;
}
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Possible output:
Rounding using to-nearest rounding:
nearbyint (2.3) = 2.0
nearbyint (3.8) = 4.0
nearbyint (-2.3) = -2.0
nearbyint (-3.8) = -4.0
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See also
- rint
- Round to integral value (function)
- lrint
- Round and cast to long integer (function)
- round
- Round to nearest (function)
- floor
- Round down value (function)
- ceil
- Round up value (function)
- trunc
- Truncate value (function)