Ploting heatmaps in function of time

Hello,

I have search a solution for my problem but didn't find any that suited my problem.

Basically, I have a 3D matrix (18x17x2000) representing heatmap of a sample on the 2000 frames of the measurement. I would like to plot it all but with a slider or a cursor or whatever that could allow me to chose which frame I want to display, allowing me to easily go through my data.

I tried the VideoWriter tool but it gives really blurry and not convenient result. The goal is to keep the heatmap representation.

Thank you for your help,

Answer 1

[Adam Danz]

This demo produces a heatmap with random data and a slider that controls which slice of the 3rd dimension of data to plot.

Demo based on a similar solution for bar plots but uses a ValueChangingFcn to update the heatmap and title as the slider changes instead of a ValueChangedFcn which is evoked after making a change to the slider.

data = rand(20,20,2000);  % data with size n*m*k

fig = uifigure();
uip = uipanel(fig,'Position', [20 100 500 300]);
heatObj = heatmap(uip, data(:,:,1));
title(heatObj, 'Frame #1');
n = size(data,3);
uis = uislider(fig,'Position',[50 50 450 3],...
    'Value',1, ...
    'Limits', [1,n], ...
    'MajorTicks', [1, 200:200:n], ...
    'MinorTicks', []);
uis.ValueChangingFcn = {@sliderChangingFcn, data, heatObj};


function sliderChangingFcn(~,event,data,heatObj)
    % Update heatmap and title with new selection of data
    value = round(event.Value);
    heatObj.ColorData = data(:,:,value);
    heatObj.Title = sprintf('Frame #%d',value);
end

Tip: set clim so the colorbar limits do not jump around as the heatmap data are updated. This is seen in the GIF below.

[Julien Maxime]

It is exactly what I needed, thank you very much. Hoping this can help others with the same issue as mine.

[Julien Maxime]

I have another related question. Do you think it is possible to make the heatmap change as the cursors is moving and not only when the cursos is release ?

[Adam Danz]

Try replacing the valueChangedFcn with the valueChangingFcn.

https://www.mathworks.com/help/matlab/ref/matlab.ui.control.slider-properties.html#buh_e24-86_sep_shared-ValueChangingFcn

[Julien Maxime]

Thank you very much for your help really. I dare ask one last question. Here is the relevant code part of the plot:

data = M;
fig = uifigure(); 
uip = uipanel(fig,'Position', [20 100 500 300]); 
hh = heatmap(uip, data(:,:,1),'Colormap', hsv,'CellLabelColor', 'none','ColorLimits', [-360 50]);
title(hh, 'Electrode Fluorescence Heatmap - Frame #1');
n = size(data,3);
uis = uislider(fig,'Position',[50 50 450 3],...
    'Value',1, ...
    'Limits', [1,n], ...
    'MajorTicks', 0:200:n, ...
    'MinorTicks', []);
%valueChangedFcn for actualisation only when cursor is dropped

uis.ValueChangingFcn = {@sliderChangingFcn, uip, data};
function sliderChangingFcn(h,~,uip,data)
   value = round(h.value);   
   hh = heatmap(uip,data(:,:,Value), 'Colormap', hsv, 'CellLabelColor', 'none', 'ColorLimits', [-360 50]);
   title(hh, sprintf('Electrode Fluorescence Heatmap - Frame #%s',num2str(value)))
end

However, when i slide the cursor it changes the plot one time during the sliding but then stays and lag/block on this last plot. I have to drop it and move it again to diplay a new plot again. I found this guy who had a similar problem but I don't know how to adapt it to my situation: https://www.mathworks.com/matlabcentral/answers/521185-how-to-continuously-change-the-plotted-data-according-to-the-value-obtained-from-a-uislider-compon

Can you help me ?

Thank you very much.

[Adam Danz]

I've updated my answer to use a ValueChangingFcn. The updated answer also updates the existing heatmap rather than recreating it which is much more efficient.

[Julien Maxime]

Thank you it is perfect!

[Adam Danz]

You may want to set clim so the colorbar limits do not jump around as you update heatmap. You can see this happening in the GIF I shared.

[Patricia Darling]

Where would I embed clim in the code above. I tried making it stand alone in the main script and in the function and it doesn't seem to be impacting anything.