Arithmetic Operators

double factorial function

Usage

ldfactorial(x)

dfactorial(x)

Arguments

x

a numeric scalar or vector

Value

dfactorial(x) returns the double factorial, that is \(x\!\! = 1 * 3 * 5 * \ldots * x \) and ldfactorial(x) is the natural logarithm of it.

See also

factorial, howmanytrees

Author

Klaus Schliep klaus.schliep@gmail.com

Examples

dfactorial(1:10)
#>  [1]    1.000000    1.595769    3.000000    6.383076   15.000000   38.298459
#>  [7]  105.000000  306.387671  945.000000 3063.876713