fact2
function fact2( x ) --> res
Description
Returns the double factorial of x.
Parameters
- x
-
The nonnegative number for which you want the double factorial. If number is not an integer, it is truncated.
Return Values
- res
-
The double factorial of x.
Code
--ZFUNC-fact2-v1 local function fact2( x ) --> res if x < 0 then return math.sqrt( x ) end x = math.floor( x ) if x == 0 or x == 1 then return 1 else return x * fact2( x-2 ) end end return fact2
Examples
local t = require( "tapered" ) local fact2 = require( "fact2" ) t.is( 48, fact2( 6 ) ) t.is( 105, fact2( 7 ) ) t.is( 1, fact2( 0 ) ) t.done()