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IsPowerOfTwo

Decides whether vector elements are integral powers of two (returns NA if not).

DESCRIPTION

This function checks to see whether its input is a power of two. If it is then it returns that power otherwise it returns NA.

USAGE

IsPowerOfTwo(n)

REQUIRED ARGUMENTS

n: Vector of numbers that are to be checked whether it is a power of two.

OPTIONAL ARGUMENTS

None.

VALUE

If n is a power of two, then the power is returned otherwise NA is returned.

SIDE EFFECTS

None

DETAILS

Function takes the log of the input, divides this by log(2) and if the result is integral then it knows the input is true power of two.

RELEASE

EXAMPLES

#
# Try and see whether 1,2,3 or 4 are powers of two! 
#
IsPowerOfTwo(1:4)
# [1]  0  1 NA  2
#
# Yes, 1,2 and 4 are the 0, 1 and 2nd power of 2. However, 3 is not an
# integral power of two.