GAMMALN
TheGAMMALN
function returns the natural logarithm of the absolute value of the Gamma function, Γ(x). The Gamma function is defined as an extension of the factorial function to complex and real numbers. The function is commonly used in probability theory and statistics to compute probabilities and to model continuous distributions such as the chisquared and F distributions.
 How to use
GAMMALN
formula?  Examples of using
GAMMALN
formula GAMMALN
formula not working? Similar formulas to
GAMMALN
Usage
Use the GAMMALN
formula with the syntax shown below, it has 1 required parameter:
 value (required):
The value for which to compute the natural logarithm of the absolute value of the Gamma function. Value must be positive and cannot be 0.
Examples
Here are a few example use cases that explain how to use theGAMMALN
formula in Google Sheets.
Compute probabilities for the chisquared distribution
The chisquared distribution is used to model the sum of squared random variables. The GAMMALN
function can be used to compute probabilities for this distribution by first computing the natural logarithm of the Gamma function and then using it in the probability density function.
Compute probabilities for the F distribution
The F distribution is used to model the ratio of variances of two populations. The GAMMALN
function can be used to compute probabilities for this distribution by first computing the natural logarithm of the Gamma function and then using it in the probability density function.
Compute the logarithm of large factorials
The Gamma function is an extension of the factorial function to real and complex numbers. The GAMMALN
function can be used to compute the natural logarithm of large factorials by first computing the natural logarithm of the Gamma function and then applying Stirling's approximation.
Common Mistakes
GAMMALN
not working? Here are some common mistakes people make when using the GAMMALN
Google Sheets Formula:
Not providing a value
This will return an error if the value is not provided as it is a required argument.
Providing a nonnumeric value
This will return an error if the value provided is not a number.
Using a negative value
This will return an error if the value provided is negative.
Related Formulas
The following functions are similar to GAMMALN
or are often used with it in a formula:

GAMMA
The GAMMA function returns the Gamma function evaluated at the input value. The Gamma function is a commonly used function in mathematics, and is used in many statistical calculations. It is defined as the integral of t^(x1)*e^(t) from 0 to infinity. The GAMMA function can be used to calculate probabilities of certain events in statistical distributions.

LN
The
LN
formula returns the natural logarithm of a given value. The natural logarithm is the logarithm to the base e, where e is an irrational number approximately equal to 2.71828. The formula is commonly used in mathematical and scientific calculations. 
EXP
The
EXP
function returns the result of e raised to the power of a given exponent. This function is commonly used in mathematical and scientific calculations. 
ERF
The
ERF
function calculates the error function of a given value. The error function returns the probability of a normal variable with a mean of zero and a standard deviation of one falling between two values. This function is commonly used in statistics and engineering applications.
Learn More
You can learn more about the GAMMALN
Google Sheets function on Google Support.