How do you include 0's in confusionchart?

Previously posted but not answered: https://www.mathworks.com/matlabcentral/answers/1667539-how-do-i-display-zeros-in-confusion-chart

Is there a way to display 0's in a confusionchart?

i have searched through MATLAB document for confusionchart to no avail, and a Google search brought me to the first question but no other answers. :(

I am attaching the code that I used to get the confusion chart, and any guidance will be appreciated! Otherwise manually adding a 0's in power point will be my option. Thanks!

path = 'X:\GC_Experiments2\MelioData\Melio_Clean_6_predictions.csv';
data = readtable(path);
group1 = table2array(data(:,2));
group2 = table2array(data(:,3));
D = unique(group1);
labels = [D(1,1),D(2,1),D(3,1),D(4,1),D(5,1),D(6,1),D(7,1),D(8,1),D(9,1)];
C = confusionmat(group1,group2,'Order',labels);

figure;
confusionchart(C,'OffDiagonalColor','b');

[Rik]

Please format your code as code and attach your data. That way we can run your exact code and get the same results.

[Sangmin]

Did you find the solution?

[April Aralar]

Nope! I ended up having to manually add the 0's in Powerpoint which was a little sad

[Mike Croucher]

I took a look just now and couldn't figure out anything from the documentation so I have raised this with development as an enhancement request. I agree, no one should be manually adding 0's with Powerpoint!

Answer 1

[Mike Croucher]

This functionality is now available in MATLAB R2026a. You can get a confusionchart to show zeros using the ZerosVisible property.

g1 = [3 2 2 3 1 1]';	% Known groups
g2 = [4 2 3 NaN 1 1]';	% Predicted groups
C = confusionmat(g1,g2)

C = 4×4

2 0 0 0 0 1 1 0 0 0 0 1 0 0 0 0

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confusionchart(C,ZerosVisible="on")

Answer 2

[Hitesh]

Hi April,

I too encountered the similar issue with the "confusionchart", the workaround that worked for me was to use "heatmap". After creating the confusion matrix and display it using a "heatmap".This will ensure that all values, including zeros, are visible.

Kindly refer to the following code:

% Create a heatmap for the confusion matrix
h = heatmap(confMat);

% Use a modified colormap for lighter colors
originalColormap = parula; % Use 'hot', 'parula', or another colormap
lightColormap = 0.5 + 0.5 * originalColormap; % Lighten the colormap

% Apply the lighter colormap
h.Colormap = lightColormap;

% Customize the heatmap appearance
h.ColorbarVisible = 'off';
h.CellLabelColor = 'black';  % Ensure labels are visible
h.CellLabelFormat = '%d';    % Display as integers

% Add titles and labels for clarity
h.Title = 'Confusion Matrix';
h.XLabel = 'Predicted Class';
h.YLabel = 'True Class';

For more information regarding the "heatmap", kindly refer to the following MATLAB documenation:

https://www.mathworks.com/help/matlab/ref/heatmap.html