xscrambl.m

biomedical stuffs...

function  xscram=xscrambl(x)
%  xscram=xscrambl(x)
%  scrambles a data file using uniform random numbers to generate indices
% works with vectors only
%
%	This program is distributed as a supplement to the book
%	"Biomedical Signal Processing and Signal Modeling" by E. N. Bruce,
%	published by Wiley, 2000.  It is provided for educational use only.
%  While every effort has been made to insure its suitability to illustrate
%  principles described in the above book, no specific feature or capability 
%  is implied or guaranteed.
xscram=zeros(size(x));
xtmp=x;kl=length(x);ran1=zeros(100,1);
rand('seed',sum(100*clock));
for j=1:kl
	win=0;
	while j ~= kl+1 & win == 0
	ran1=rand(100,1); indx=max([round(99*rand),1]);
	ran2=ran1(indx,1);
	ix=round(kl*ran2);
	if ix <= kl & ix > 0
		if xtmp(ix) ~= -9999
			xscram(j)=xtmp(ix);
			xtmp(ix)=-9999;
			win=1;
		end
	end
	end  % of while loop
end   % of main for loop