Returns the value of the expression MathLog(1+x).

double  MathLog1p(
   double  value      // value to take the logarithm



[in]  The value, the logarithm of which is to be calculated.

Return Value

The natural logarithm of the value (value + 1) if successful. If value is < -1, the function returns NaN (undefined value). If value is equal to -1, the function returns INF (infinity).


At values of x close to 0, the MathLog1p(x) function generates much more accurate values than the MathLog(1+x) function.

Instead of the MathLog1p() function you can use the log1p() function.

See also

Real types (double, float)