how to plot confusion matrix from confusion matrix?

18 views (last 30 days)
Hassan Ashraf
Hassan Ashraf on 5 Dec 2019
Commented: Akira Agata on 5 Dec 2019
I have a confusion matrix, in numbers. I want to plot the percentage classification accuracies. I found some code from fileExchnage, but its calculating percentages wrongly. Please help to figure it out.
load confmat.mat
numlabels = size(confmat, 1); % number of labels
% calculate the percentage accuracies
confpercent = 100*confmat./repmat(sum(confmat, 1),numlabels,1);
% plotting the colors
imagesc(confpercent);
ylabel('Output Class'); xlabel('Target Class');
% set the colormap
colormap(flipud(gray));
% Create strings from the matrix values and remove spaces
textStrings = num2str(confpercent(:), '%.1f%\n%d\n');
textStrings = strtrim(cellstr(textStrings));
% Create x and y coordinates for the strings and plot them
[x,y] = meshgrid(1:numlabels);
hStrings = text(x(:),y(:),textStrings(:), ...
'HorizontalAlignment','center', 'FontSize', 38);
% Get the middle value of the color range
midValue = mean(get(gca,'CLim'));
% Choose white or black for the text color of the strings so
% they can be easily seen over the background color
textColors = repmat(confpercent(:) > midValue,1,3);
set(hStrings,{'Color'},num2cell(textColors,2));
  1 Comment
Akira Agata
Akira Agata on 5 Dec 2019
If you have 'Deep Learning Toolbox' or 'Statistics and Machine Learning Toolbox', you can use confusionchart function to plot the chart easily.

Sign in to comment.

Answers (0)

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by