polar dendogram with labels

I am having difficulties putting labels on polar dendogram

using code by sam on below

https://www.mathworks.com/matlabcentral/fileexchange/21983-draw-a-polar-dendrogram

and assistance in stackoverflow

https://stackoverflow.com/questions/14856715/represent-a-radial-dendrogram-in-matlab

X= rand(5,20); Y= pdist(X,'cityblock'); Z= linkage(Y,'average'); clf polardendrogram(Z,labels',{'a', 'b', 'c' , 'd', 'e'},'colorthreshold','default'); zoom(0.8); view(2);

but my graphs labels not coming out nicely

Answer 1

[Himanshu]

Hey Ann,

I went thourgh Sam's code on file exchange and was able to make the labels work. I made only little changes to its code which are as follows:

1. Function Signature: Added labels as an input parameter.
2. Label Handling: Modified the loop that relabels leaves to use the provided labels array.

This is the modified code:

function [h,T,perm] = polardendrogram(Z, labels, varargin)
    %POLARDENDROGRAM plots a polar dendrogram plot, taking same options as
    %dendrogram and giving same outputs.
    % Example:
    % X= rand(100,2);
    % Y= pdist(X,'cityblock');
    % Z= linkage(Y,'average');
    % [H,T] = polardendrogram(Z,'colorthreshold','default');

    % Plot a normal dendrogram
    [h,T,perm] = dendrogram(Z, varargin{:});
    
    % Get x and y ranges
    xlim = get(gca,'XLim');
    ylim = get(gca,'YLim');
    minx = xlim(1);
    maxx = xlim(2);
    miny = ylim(1);
    maxy = ylim(2);
    xrange = maxx - minx;
    yrange = maxy - miny;
    
    % Reshape into a polar plot
    for i = 1:size(h)
        xdata = get(h(i),'XData');
        ydata = get(h(i),'YData');
        % Rescale xdata to go from pi/12 to 2pi - pi/12
        xdata = (((xdata - minx) / xrange) * (pi * 11 / 6)) + (pi / 12);
        % Rescale ydata to go from 1 to 0, cutting off lines
        % which drop below the axis limit
        ydata = max(ydata, miny);
        ydata = 1 - ((ydata - miny) / yrange);
        % To make horizontal lines look more circular,
        % insert ten points into the middle of the line before
        % polar transform
        newxdata = [xdata(1), linspace(xdata(2), xdata(3), 10), xdata(4)];
        newydata = [ydata(1), repmat(ydata(2), 1, 10), ydata(4)];
        % Transform to polar coordinates
        [xdata, ydata] = pol2cart(newxdata, newydata);
        % Reset line positions to new polar positions
        set(h(i), 'XData', xdata);
        set(h(i), 'YData', ydata);
    end
    
    % Relabel leaves
    for i = 1:length(labels)
        [x, y] = pol2cart((((i - minx) / xrange) * (pi * 11 / 6)) + (pi * 1 / 12), 1.1);
        text(x, y, labels{i}, 'HorizontalAlignment', 'center');
    end
    
    % Add and label gridlines
    hold on
    lineh(1) = polar([0,0], [0,1], '-');
    lineh(2) = polar(linspace(0, 2 * pi, 50), ones(1, 50), ':');
    lineh(3) = polar(linspace(0, 2 * pi, 50), ones(1, 50) * 0.75, ':');
    lineh(4) = polar(linspace(0, 2 * pi, 50), ones(1, 50) * 0.5, ':');
    lineh(5) = polar(linspace(0, 2 * pi, 50), ones(1, 50) * 0.25, ':');
    set(lineh, 'Color', [0.5, 0.5, 0.5]);
    for i = 1:4
        [x, y] = pol2cart(0, i / 4);
        str = sprintf('%2.1f', ((maxy - miny) * (4 - i) / 4) + miny);
        text(x, y, str, 'VerticalAlignment', 'bottom');
    end
    
    % Prettier
    set(gca, 'XLim', [-1.5, 1.5], 'YLim', [-1.5, 1.5], 'Visible', 'off');
    view(3)
    axis fill
    daspect([1, 1, 100]);
    zoom(2.8);
end

And this is how you may utilize the above fucntion:

X = rand(5, 20); 
Y = pdist(X, 'cityblock'); 
Z = linkage(Y, 'average'); 
labels = {'a', 'b', 'c', 'd', 'e'}; % Define your labels here
clf;
polardendrogram(Z, labels, 'colorthreshold', 'default'); 
zoom(0.8); 
view(2);

Hope this helps!