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% Project     : PON_HD
% Module      : ScatterColormap
% Description : constellation scatterplot with colormap
%
% References  :
%
%Version|Date    |author|Description
%-------|--------|------|-------------------------------------------------------
%01.01  |20200923|L,YM  |Initial version
%-------|--------|------|-------------------------------------------------------
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function SurfColormap(ax,x,y)

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%% coeffients
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%test
MaxLength  = 1e5; %1e4 for QuickCheck, 1e5 for accurate check.
DataLength = min(length(x), MaxLength);

x = x(end - DataLength + 1: end);
y = y(end - DataLength + 1: end);


DivideNum = 200;
% DataMax = max(max(abs(x)),max(abs(y)));
DataMax = 1.9;
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%% Scatter Plot
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Edges = linspace(-DataMax, DataMax, DivideNum + 1);
Constellation = histcounts2(x, y, Edges, Edges);

%normalization
Constellation = Constellation ./ max(Constellation, [], 'all');
Constellation = ceil(Constellation .* 63) + 1; %1~256. 1=background

%rotation
Constellation = rot90(Constellation);
Constellation = flipud(Constellation);

%% plot

A = linspace(-DataMax, DataMax, DivideNum);
pcolor(ax, A, A, Constellation);
% xlabel('I'); 
% ylabel('Q');

colormap parula
map = colormap;
map(1,:) = ones(1,3);% white background
colormap(map)

shading flat%interp%
axis equal

end%function