# FACT()

Calculates faculty

Syntax

  FACT (nNumber) -> nFaculty

Arguments

  <nNumber> number between 0 and 21

Returns

  <nFaculty> the faculty of <nNumber>

Description

  The function FACT() calculates the faculty to the integer given in <nNumber>. The faculty is defined as n! = 1*2*...*n and is often used in statistics. Note, that faculties above 21 are too big so that the function must return a -1.

Examples

          ? fact (0)  --> 1
          ? fact (1)  --> 1
          ? fact (4)  --> 24
    Tests
          fact (0) == 1
          fact (1) == 1
          fact (4) == 24

Status

  Ready

Compliance

  FACT() is compatible with CT3's FACT().

Platforms

  All

Files

  Source is math.c, library is libct.