Class FactDouble

  • All Implemented Interfaces:
    FreeRefFunction, Function, Function1Arg

    public class FactDouble
    extends Fixed1ArgFunction
    implements FreeRefFunction
    Implementation for Excel FACTDOUBLE() function.

    Syntax:
    FACTDOUBLE (number)

    Returns the double factorial of a number.

    Number is the value for which to return the double factorial. If number is not an integer, it is truncated.

    Remarks

    • If number is nonnumeric, FACTDOUBLE returns the #VALUE! error value.
    • If number is negative, FACTDOUBLE returns the #NUM! error value.
    Use a cache for more speed of previously calculated factorial
    • Constructor Detail

      • FactDouble

        public FactDouble()
    • Method Detail

      • factorial

        public static BigInteger factorial​(int n)
      • evaluate

        public ValueEval evaluate​(ValueEval[] args,
                                  OperationEvaluationContext ec)
        Specified by:
        evaluate in interface FreeRefFunction
        Parameters:
        args - the pre-evaluated arguments for this function. args is never null, nor are any of its elements.
        ec - primarily used to identify the source cell containing the formula being evaluated. may also be used to dynamically create reference evals.
        Returns:
        never null. Possibly an instance of ErrorEval in the case of a specified Excel error (Exceptions are never thrown to represent Excel errors).