C <math.h> - logb() Function
The C <math.h> logb() function returns the logarithm of |x| (mod of argument), using FLT_RADIX as base for the logarithm.
On most platforms, FLT_RADIX is 2, which makes this function equivalent to log2() function for positive values.
Syntax
double logb (double x); float logbf (float x); long double logbl (long double x);
Parameters
x |
Specify the value to calculate logarithm. |
Return Value
Returns the base-FLT_RADIX logarithm of |x|.
Example:
In the example below, logb() function is used to calculate the base-FLT_RADIX logarithm of absolute value of given numbers.
#include <stdio.h>
#include <math.h>
int main (){
printf("logb(10) = %f\n", logb(10));
printf("logb(-10) = %f\n", logb(-10));
return 0;
}
The output of the above code will be:
logb(10) = 3.000000 logb(-10) = 3.000000
❮ C <math.h> Library
