demo.m

% add Fast Gauss Transform path (change to your local directory)
% addpath(genpath('FGT'));

tic

N = size(data,1);
sigma  = 0.5;                                           % the choice of sigma depends on the dataset

q = ones(1,N);                                          % weight for each point, set to 1 as default
epsilon = 1e-4;                                         % tolerance for the accuracy of Gauss Transform approximation
density = figtree( data', sigma, q, data', epsilon)/N;  % density is the color used in scatter plot   

% visulaization
scatter3(data(:,1),data(:,2), data(:,3), 1, density, '.');
colormap(hot);
set(gca,'Color','k')                                    % the background should be black for the hot colormap
axis equal, axis square

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