MATLAB: Legend in for loop

legendMATLABplot

Dear all, I would like to insert legend inside the for loop plot. In this plot same class repeated many times. I want to display one categorry at a time.
for i = 1:udClass
    Legend{i} = ['Class' int2str(i)];
end
for i = 1:N
    idClass = classVec(i);
    plot(X(:,i), 'color', colors(idClass,:))
    x = floor(ndata/2);
    y = 1- (i-1)/N;
    text(x, y, int2str(i), 'color', colors(idClass,:), 'VerticalAlignment', 'top',...
    'HorizontalAlignment','center','FontSize',8)
end
legend(Legend, 'Location', 'Southeast');
With this code I got like shown
in which I got color repeated for different classes but I want each class with assigned colors. Could you please help me in this regard. Thanks

Best Answer

Save the handles of your plotted lines, then pass the specific handles of lines with a unique class to the legend command:
for i = 1:udClass
    Legend{i} = ['Class' int2str(i)];
end
h = gobjects(N,1); % h = zeros(N,1) if R2014a or earlier
for i = 1:N
    idClass = classVec(i);
    h(i) = plot(X(:,i), 'color', colors(idClass,:))
    x = floor(ndata/2);
    y = 1- (i-1)/N;
    text(x, y, int2str(i), 'color', colors(idClass,:), 'VerticalAlignment', 'top',...
    'HorizontalAlignment','center','FontSize',8)
end
[~,idx] = unique(classVec);
legend(h(idx), Legend, 'Location', 'Southeast');
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