CODEWITHSUNDEEP
matlabplotlabelbar-chart
Javier
Javier

Reputation: 1141

How can I adjust 3-D bar grouping and y-axis labeling in MATLAB?

I have a 3D plot like this:

alt text

On the y-axis of the plot, each group of three bars refers to the same parameters: x1, x2, x3. I would like to have a spacing on the y-axis for each group of three bars, so that it becomes more clear that those bars are referring to the same parameters. At the same time, I would like to put a label on the y-axis for each group of three bars. For example, the following label layout for the y-axis would be desired:

x1 x2 x3   x1 x2 x3   x1 x2 x3
  grid1     grid2      grid3

Any suggestions are more than welcome! The code that I used to plot the bars is given below:

Z = rand(9,5);
h = bar3(Z);
[r c] = size(Z);

zdata = [];
for i = 1:c
    zdata = [];
    for j = 1:r
        zdata = [zdata; ones(6,4)*Z(j,i)];
    end
set(h(i),'Cdata',zdata)
end
colormap
colorbar
set(gca,'YTickLabel',['x1';'x2';'x3';'x1';'x2';'x3';'x1';'x2';'x3']);
view([-64 44]);

Upvotes: 7

Views: 12438

Answers (1)

gnovice
gnovice

Reputation: 125874

You can add spacing in between your groups of bars by specifying an additional input to bar3 indicating the positions at which to place the columns of bars along the y axis. You can also plot additional text in your axes using the function text:

Z = rand(9, 5);              % Some random sample data
[r, c] = size(Z);            % Size of Z
Y = [1 2 3 5 6 7 9 10 11];   % The positions of bars along the y axis
C = mat2cell(kron(Z, ones(6, 4)), 6*r, 4.*ones(1, c)).';  %' Color data for Z

hBar = bar3(Y, Z);           % Create the bar graph
set(hBar, {'CData'}, C);     % Add the color data
set(gca, 'YTickLabel', {'x1' 'x2' 'x3'});  % Modify the y axis tick labels
view(-70, 30);               % Change the camera view
colorbar;                    % Add the color bar
text(-2, 2, 'grid1');        % Add "grid1" text
text(-2, 6, 'grid2');        % Add "grid2" text
text(-2, 10, 'grid3');       % Add "grid3" text

enter image description here

Note that you may have to adjust the x and y values of your text objects to get them to render where you want for the given camera view that you choose.

EDIT:

If you'd also like to display the values above each bar, you can do that by adding the following to the above code:

hText = text(kron((1:c).', ones(r, 1)), ...    %' Column of x values
             repmat(Y(:), c, 1), ...            % Column of y values
             Z(:)+0.05, ...                     % Column of z values
             num2str(Z(:)), ...                 % Text strings
             'HorizontalAlignment', 'center');  % Center the strings

It should be pointed out that having this much plotted text gets a little messy, since some of the text will be overlapping or hidden behind the bars. The text is also a bit redundant, since the color of the bars is really meant to show the values.

Upvotes: 10

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