MATLAB: Plot a heatmap from a matix

Question

I implemented the minutia heat map presented in this paper (page 7): https://arxiv.org/pdf/1909.09901.pdf

The result is that i have 6 matrixes and i am looking for a way to plot these as shown in the paper (same page), like this:

Basically, the low values is presented in dark, and it gets lighter when it increase.

Answer 1

You are using H for rows and W for columns

M1 = zeros(H,W);
% ...


for i = 1 : W
    for j = 1 : H
        % ...
        M1(i,j) = Hijk;        % looks like mistake

You can use cells to create 6 matrices automatically

MM = cell(6,1);
M = zeros(H,W);
for k = 1:6
    for i 
        for j
            for t
                % do stuff
            end
            % ...
            M(i,j) = %...
        end
    end
    MM{k} = M;
end

After you found max and min values (global) use loop to visualize

for k = 1:6
    figure(k)
    heatmap(MM{k});
    caxis([minx maxx])
    colormap gray
end