ComputeDivFact: Compute the ratio of factorials.

In primefactr: Use Prime Factorization for Computations

Description

Compute the ratio of factorials using Prime Factorization. For example, ComputeDivFact(c(a, b), c(d, e, f)) computes \frac{a! b!}{d! e! f!}.

Usage

ComputeDivFact(num, deno = NULL, out.log = FALSE)

Arguments

num	The vector of all numbers which have their factorials in the numerator.
deno	The vector of all numbers which have their factorials in the denominator. Default is NULL, there is only a numerator.
out.log	Is the logarithm of the result returned instead? Default is FALSE.

Value

The result of the ratio or its logarithm if out.log = TRUE.

See Also

choose

Examples

choose(100, 20)
ComputeDivFact(100, c(20, 80))
lchoose(100, 20)
ComputeDivFact(100, c(20, 80), out.log = TRUE)

factorial(100)
ComputeDivFact(100)
lfactorial(100)
ComputeDivFact(100, out.log = TRUE)

primefactr documentation built on May 1, 2019, 7:32 p.m.