<cmath>
double ldexp ( double x, int exp );
float ldexp ( float x, int exp );
long double ldexp ( long double x, int exp );
Generate number from significand and exponent
Returns the resulting floating point value from multiplying x (the significand) by 2 raised to the power of exp (the exponent).
Parameters
- x
- Floating point value representing the significand.
- exp
- Value of the exponent.
Return Value
The function returns:
x * 2 exp
Portability
In C, only the double version of this function exists with this name.
Example
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/* ldexp example */
#include <stdio.h>
#include <math.h>
int main ()
{
double param, result;
int n;
param = 0.95;
n = 4;
result = ldexp (param , n);
printf ("%f * 2^%d = %f\n", param, n, result);
return 0;
}
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Output:
0.950000 * 2^4 = 15.200000
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See also
| frexp | Get significand and exponent (function) |
| log | Compute natural logarithm (function) |
| pow | Raise to power (function) |
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