% graycode.m
% convert from (value,length) to a bitstring.
% Usage:
%   c = graycode(9, 8)
%   print_without_spaces(c)
% returns the 8 bits
%   c = [ 0     0     0     0     1     1     0     1 ]
%   00001101
% This has a value of 9 when interpreted as gray code.
% by John C. Kieffer
% http://www.ee.umn.edu/users/kieffer/programs.html
% documented in
% ftp://oz.ee.umn.edu/users/kieffer/seminar/notes1.ps
% more documentation by David Cary 1999-06-26
%
% See also BINARYCODE, BINARY_TO_INDEX, PRINT_WITHOUT_SPACES.
function y = graycode(i,L)
x=binarycode(i,L);
y(1)=x(1);
for j=2:L;
   if x(j-1)==1
      y(j)=1-x(j);
   else
      y(j)=x(j);
   end
end