function [x,y,z,RepeatIndeces,repeats Q]=redundnt(x,y,z)
% 
% [x,y,z,RepeatIndeces,repeats Q]=redundnt(x,y,z)
%
% [redundnt] averages all z's which have the same x and y coordinates, and 
% truncates the length of x and z by number of repeats. 
% {repeats} stores the coordinate(s) of the repeated stations, and 
% the number of occurences at each station
%  Q is the std of repeats/mean of repeats

%***********************************************************************************
%
%                              Jim Merriam
%                       University of Saskatchewan
%                          jim.merriam@usask.ca
%                              (Jan 1997)  
%                            (last Sept 1998)
%
%***********************************************************************************
repeats=[]; % initialize
x1=x;	% 
y1=y; % working copies of input vectors
z1=z; %

n=0; % index for number of repeat locations

  for j=1:length(x)	% cycle through input vector
  k=find(x(j)==x1 & y(j)==y1) ;	% find indices of repeats
    if length(k)>1	% test for existence of repeats
    n=n+1;
    repeats(n,1)=x(j);
    repeats(n,2)=y(j);
    repeats(n,3)=z(j);
    repeats(n,4)=length(k); % number of repeats at each location
    z1(k)
    Q(j)=std(z1(k))/mean(z1(k));
    z1(j)=mean(z1(k));      % first of repeats=average of repeats
    x1(k(2:length(k)))=NaN*k(2:length(k)); % NaN all repeats
    y1(k(2:length(k)))=NaN*k(2:length(k)); % NaN all repeats
    end
  end
  
RepeatIndeces=find(isnan(x1)); % find Nan's in working x
x1(RepeatIndeces)=[]; % 
y1(RepeatIndeces)=[]; % clear all NaN's (repeats)
z1(RepeatIndeces)=[]; % 
x=x1;
y=y1;	% copy working back to original
z=z1;