GrayCodePosition

Lightweight package for Gray codes and their transient index sequences.

Usage

Gray codes can be easily generated.

using GrayCodePosition
code = GrayCode(3) # Gray code (collection of all codewords) over 3 bits
for c in code println(bitstring(c)[end-2:end]) end
#= 
000
001
011
010
110
111
101
100
=#

Note the position of the bit changing between two successive codewords: 1, 2, 1, 3, 1, 2, and finally 1. These positions are called the transient indices. They can be generated and iterated as follows

using GrayCodePosition
code = GrayCode(3)
gcp = GrayCodePositions(code) # Equivalently, gcp = diff(code)
collect(gcp)'
# 1×7 adjoint(::Vector{Int64}) with eltype Int64:
# 1  2  1  3  1  2  1