Compute the Second Derivative of the Logarithmic value of the gamma Function in R Programming – trigamma() Function
trigamma()
function in R Language is used to calculate the second derivative of the natural logarithm of the gamma value calculated using the gamma function.
trigamma Function is basically,
trigamma(x) = d2(ln(factorial(n-1)))/dx2
Syntax: trigamma(x)
Parameters:
x: Numeric vector
Example 1:
# R program to find second derivative # of the lgamma value # Calling the trigamma() Function trigamma( 2 ) trigamma( 4 ) trigamma( 5.2 ) |
Output:
[1] 0.6449341 [1] 0.283823 [1] 0.2119756
Example 2:
# R program to find second derivative # of the lgamma value # Creating a vector x < - c( 2.3 , 3 , 1.2 ) # Calling the trigamma() Function trigamma(x) # Calling trigamma() function # on negative values trigamma( - 2.3 ) trigamma( - 2 ) |
Output:
[1] 0.5425375 0.3949341 1.2673772 [1] 14.72591 [1] Inf