The Excel Gammaln.Precise function returns the natural logarithm of the Gamma Distribution.
The function is new in Excel 2010 and so is not available in earlier versions of Excel. However, the Gammaln.Precise function is simply a new version of the Gammaln function, that is available in earlier versions of Excel.
The syntax of the function is :
where x is the positive numeric value, at which you want to evaluate the function.
The above chart on the right shows the natural logarithm of the gamma distribution for values of x between 0 and 10.
If you want to calculate the value of this function at x = 4.5, the Excel Gammaln.Precise function can be used to do this, as shown below:
This gives the result 2.453736571.
Further examples of the Excel Gammaln.Precise function are provided on the Microsoft Office website.
If you get an error from the Excel Gammaln.Precise function this is likely to be one of the following :
|#NUM!||-||Occurs if the supplied value of x is ≤ 0|
|#VALUE!||-||Occurs if the supplied value of x is non-numeric|