MATLAB: How and where to place the legend box in a “tiledlayout”

tiledlayout

Dear community,

I have to plot four plots usinusing tiledlayout. The legend is the same for all four plots. Logically, I woudl like find the way somehow omit the legend dublicatiion in each plot. Placing the legend in one, singe figure (Image below) is also not a solution.

Is there any idea how to please the legend, for example, below the main title "Comparison of 2D histograms".

If any other idea will appeare, please share them,

Best Answer

Starting in 2020b, Legend and Colorbar have a Layout property that gives you more control of positioning them in a TiledChartLayout. Here's an example of placing a legend in the north tile, under the title.

tl = tiledlayout('flow');
nexttile
plot(rand(1,10));
hold on
plot(rand(1,10));
nexttile
plot(rand(1,10));
hold on
plot(rand(1,10));
leg = legend('Orientation', 'Horizontal');
leg.Layout.Tile = 'north';
title(tl, 'Legend in the north tile');

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MATLAB: How to remove labels and grey space between subplots so that the subplots fill-up the entire figure

For MATLAB releases before R2019b, the following example code creates 2x2 plots, using the 'subplot' function and modifies the axes properties such that the subplots fill-up the entire figure window:

subplot(2,2,1);
[X,Y,Z] = peaks(20);
imagesc(Z);
ax = gca;
set(ax,'XTick',[], 'YTick', []);
ax.Position = [0 0.5 0.5 0.5];
subplot(2,2,2);
contour(X,Y,Z)
ax = gca;
set(ax,'XTick',[], 'YTick', []);
ax.Position = [0.5 0.5 0.5 0.5];
subplot(2,2,3);
imagesc(Z);
ax = gca;
set(ax,'XTick',[], 'YTick', []);
ax.Position = [0 0 0.5 0.5];
subplot(2,2,4);
contour(X,Y,Z);
ax = gca;
set(ax,'XTick',[], 'YTick', []);
ax.Position = [0.5 0 0.5 0.5];

There is a slightly elegant way of doing this in R2019b using the 'tiledlayout' function instead of 'subplot':

t = tiledlayout(2,2);
[X,Y,Z] = peaks(20);
% Tile 1
nexttile
imagesc(Z)
ax = gca;
set(ax,'XTick',[], 'YTick', []);
% Tile 2
nexttile
contour(X,Y,Z)
ax = gca;
set(ax,'XTick',[], 'YTick', []);
% Tile 3
nexttile
imagesc(Z)
ax = gca;
set(ax,'XTick',[], 'YTick', []);
% Tile 4
nexttile
contour(X,Y,Z)
ax = gca;
set(ax,'XTick',[], 'YTick', []);
t.Padding = 'none';
t.TileSpacing = 'none';

Note that the last two commands get rid of all the space between the tiled plots.

MATLAB: Legend title won’t display correctly.

OK, I see I overlooked the needed (albeit hidden) property that needed most to get where you want to go...

Try exploring from this point:

figure
hL=plot(0,0,  0,0,  0,0);             % three dummy lines to legend something
axis off                              % don't show the axis
hLg=legend({'Data Axes 1','Data Axes 2','Data Axes 3'},'FontSize',24);  % so create the base legend object
hLgT=title(hLg, "My title, and it can be long");                        % title, save handle to mung o
hLgAx=hLg.Axes;                        % retrieve the axes underlying the legend (there is still one there)
hLgLn=findobj(hLgAx,'Type','Line');    % and the handles for the lines on that axes
set(hLgLn,'LineWidth',2)               % set their width property

Thanks to Yair Altman's tool for finding the hidden properties underneath the legend...and, of course, since is all undocumented, who know how long will be before TMW changes something else altho wouldn't expect the axes to go away.

This produces a full-size figure, of course, I didn't mess with the position/size, etc., but everything should work on that axes as expected; just more complicated to get access than needs must be. Why TMW is so bent on making things more rather than less difficult is hard to comprehend.

ADDENDUM

https://www.mathworks.com/matlabcentral/fileexchange/32934-getundoc-get-undocumented-object-properties

ADDENDUM 2:

There's another hidden property PlotChildren that returns the line handles directly without having to go "handle diving" under the axis altho they're in the opposite order in the two arrays for some reason.

> hLgLn=findobj(hLgAx,'Type','Line')
hLgLn = 
  3×1 Line array:
  Line    (Data Axes 3)
  Line    (Data Axes 2)
  Line    (Data Axes 1)
>> hLg.PlotChildren
ans = 
  3×1 Line array:
  Line    (Data Axes 1)
  Line    (Data Axes 2)
  Line    (Data Axes 3)
>> all(flip(hLgLn)==hLg.PlotChildren)
ans =
  logical
   1
>>

Best Answer

Related Solutions

MATLAB: How to remove labels and grey space between subplots so that the subplots fill-up the entire figure

MATLAB: Legend title won’t display correctly.

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