Color a .ply according to Y value

I have the follwing plot that I generate: Instead of having the background be white, i want the peaks of the curves to be white and as they increase in value, I want them to get darker. Does anyone have suggestions for this. The code and data file generates is linked HERE.

[Ameer Hamza]

where is the file 'MunkS_500Hz.shd.mat'? It is also needed to run that code.

[Sushmitha Kudari]

 munkProfile = load('MunkS_500Hz.shd.mat'); 
 pressureWave = munkProfile.pressure; 
 pressureWave = abs(pressureWave); 
 squished = squeeze(pressureWave);
 logged = log(squished);
 
 
 [X,Y]=ndgrid(1:size(logged,1),1:size(logged,2 ));
 plot_mat = [X(:) Y(:) logged(:)];
 
 [remove, ~] = find(plot_mat(:,3) == -Inf); 
 plot_mat(remove,:) = []; 
 
 sorted = sortrows(plot_mat, 3);

 colorMat = addColor(sorted); 
 
 ptCloud_Coral = pointCloud(sorted,'Color',colorMat);
 
 figure
 pcshow(ptCloud_Coral);
 
 

Linking .mat : HERE

Answer 1

[Ameer Hamza]

What is the current colormap, you can reverse it by flipping the colormap matrix.

figure
p = pcshow(ptCloud);
colormap(gray)
p.Colormap = flipud(p.Colormap);

[Sushmitha Kudari]

I want the peaks of the plot to be white and the troughs to be black.

[Ameer Hamza]

How does the color change when you run the above lines? Didn't it reverse?

[Sushmitha Kudari]

It looks the same but for example I need the points at 600,0 to be white, not like this:

[Ameer Hamza]

You can create your own colormap. For example,

figure
colors = ...
    [zeros(8, 3);
    gray(10);
    ones(12, 3)];
p = pcshow(ptCloud);
colormap(colors);

creates following figure