Compute the Logarithmic Derivative of the gamma Function in R Programming – digamma() Function
digamma()
function in R Language is used to calculate the logarithmic derivative of the gamma value calculated using the gamma function.
digamma Function is basically,
digamma(x) = d(ln(factorial(n-1)))/dx
Syntax: digamma(x)
Parameters:
x: Numeric vector
Example 1:
# R program to find logarithmic derivative # of the gamma value # Calling the digamma() Function digamma( 2 ) digamma( 4 ) digamma( 5.2 ) |
Output:
[1] 0.4227843 [1] 1.256118 [1] 1.549434
Example 2:
# R program to find logarithmic derivative # of the gamma value # Creating a vector x < - c( 2.3 , 3 , 1.2 ) # Calling the digamma() Function digamma(x) # Calling digamma() function # on negative values digamma( - 2.3 ) digamma( - 2 ) |
Output:
[1] 0.6000399 0.9227843 -0.2890399 [1] 3.317323 [1] NaN Warning message: In digamma(-2) : NaNs produced