_logb, _logbl

Remonter à float.h - Index

Header File

float.h

Category

Math Routines

Prototype

double _logb(double d);

long double _logbl(long double ld);

Description

Extracts the exponential value of a double-precision floating-point argument. If the argument is denormalized, it is treated as if it were normalized.

_logbl is the long double version; it takes a long double argument and returns a long double result.

Return Value

Returns the unbiased exponent of the value passed in.

Example

#include <math.h>
#include <stdio.h>

int main(void)
{
  double result;
  double x = 8.6872;

  result = _logb(x);

  printf("The natural log of %lf is %lf\n", x, result);
  return 0;
}

Portability

	POSIX	Win32	ANSI C	ANSI C++
_logb		+
_logbl		+