function [ zq, xq ] = nanmeanquantized( x, y, z )

% (C) Demetrio Ferro demetrio.ferro@upf.edu
% Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International Public License

% find avg z at index y with value x
% try it with
% xx=[0 1 2 3 4];
% yy=[ 1 2 3 3 2 1 2 3 1 2 2 2 2 3 1 2 2 1 1 1 2 3 1 3];
% zz=[ 4 5 6 6 5 4 5 6 4 5 5 5 5 6 4 5 5 4 4 4 5 6 4 6];
% xq=[.5  1.5  2.5  3.5]
% zq=[NaN 4 5 6]; 

% or
% xx=0:.1:1;
% yy=[ 0 0 0 0 .1 .1 .1 .1 .2 .2 .2 .2 .3 .3 .3 .4 .4 .4 .5 .5 .6 .6 .6 .6 .6 .7 .7 .7 .8 .8 .8 .9 .9 .9 .9  1  1  1 1 ]
% zz=[ 1 1 1 1  2  2  2  2  3  3  3  3  4  4  4  5  5  5  6  6  7  7  7  7  7  8  8  8  9  9  9 10 10 10 10 11 11 11 11] 
% xq=[.05 .15 .25 .35 .45 .55 .65 .75 .85 .95]
% zq=[ 1 2 3.4286 NaN 5 6 7 8 9 10]

% or
% xx=[0 .25 .5 .75 1];
% yy=[.1 .3 .8 .2 .85 .4 .65 .7 .5 .9];
% zz=[0 1 1 0 1 1 0 0 1 0];
% zq=[0 1 .3333 .6667];
% xq=[0.125 0.375 0.625 0.875]; 

xq=nan(1,length(x)-1);
zq=nan(1,length(x)-1);

for ix=1:(length(x)-1)
    xq(ix)=x(ix)/2+x(ix+1)/2;
    if ix==(length(x)-1)
        zq(ix)=nanmean(z(y>=x(ix) & y<=x(ix+1)));
    else
        zq(ix)=nanmean(z(y>=x(ix) & y<x(ix+1)));
    end
end

end