Natural logarithm of the gamma function and its derivatives.
Natural logarithm of the gamma function and its derivatives.
Lgamma(x) Digamma(x) Trigamma(x)
x |
A numerical matrix or vector with positive numbers in either case. |
We have spotted that the time savings come when there are more than 50 elements, with vector or matrix.
The matrix or the vector with the resulting values.
Manos Papadakis
R implementation and documentation: Manos Papadakis <papadakm95@gmail.com>.
Abramowitz, M. and Stegun, I. A. (1972) Handbook of Mathematical Functions. New York: Dover. https://en.wikipedia.org/wiki/Abramowitz_and_Stegun provides links to the full text which is in public domain. Chapter 6: Gamma and Related Functions.
x <- matrix( rnorm(500 * 500), ncol = 500 ) a1 <- Lgamma(x) a2 <- lgamma(x) all.equal(as.vector(a1), as.vector(a2)) a1 <- Digamma(x) a2 <- digamma(x) all.equal(as.vector(a1), as.vector(a2)) x<-a1<-a2<-NULL
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