Manuals/calci/GAMMALN
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GAMMALN(x)
- Where x is the number
Description
- This function gives the natural logarithm of the absolute value of the gamma function.
- The functions digamma and trigamma are the first and second derivatives of the logarithm of the gamma function.
- This is often called the ‘polygamma’ function, The gamma, lgamma, digamma and trigamma functions are internal generic primitive functions.
- Normally the number e to the power GAMMALN(x), where x is an integer, is same as (x-1)!. *GAMMALN=LN(GAMMA(x))=,where GAMMA(x) = integral 0 to infinity t^{x-1} e^{-t} dt.and it is for all complex numbers except the negative integers and zero.
- This function will give the result as error when x is nonnumeric and x<=0.
Examples
- GAMMALN(6)=4.787491744416229
- GAMMALN(42)=114.03421178146174
- GAMMALN(1)=0.00018319639111644828(calci)=-0.00000000004171(Excel) approximate to 0.
- GAMMALN(-10)=NAN,because x<0