how to add one colorbar for the whole figure with tiled layout?

The matlab example shows that we can add colorbar to individual tiles see attached, but can we add one colorbar for the whole figure? I also have problems with adding a legend and positioning it.

Example code:

tiledlayout(2,1)
% Top plot
nexttile 
surf(peaks)
colorbar
% Bottom plot
nexttile
mesh(peaks)
colorbar

Answer 1

[Adam Danz]

To use one colorbar that represents the color values for each subplot, each subplot must use the same colormap and the same colorscale. The colorbar can be assigned to just one of the subplots or it can be a global colorbar assigned to the tiledlayout object.

Here's a demo.

tlo = tiledlayout(2,1)

tlo = 
  TiledChartLayout with properties:

    TileArrangement: 'fixed'
           GridSize: [2 1]
            Padding: 'loose'
        TileSpacing: 'loose'

  Show all properties

% Top plot
h(1) = nexttile(tlo);      % Get axis handle 
surf(h(1), peaks)

% Bottom plot
h(2) = nexttile(tlo);        % Get 2nd axis handle
surf(h(2), peaks * 2.5)

% Set colormap and color limits for all subplots
set(h, 'Colormap', jet, 'CLim', [-20 20])

% assign color bar to one tile 
cbh = colorbar(h(end)); 
% To position the colorbar as a global colorbar representing
% all tiles, 
cbh.Layout.Tile = 'east'; 

If the subplots were produced using subplot(), you can reposition the colorbar so that it is not associated with just one subplot. This example places the subplot the right of the figure, centered vertically.

 % Reposition to figure's left edge, centered vertically
  cbh.Position(1) = .95-cbh.Position(3);
  cbh.Position(2) = 0.5-cbh.Position(4)/2;
 % decrease horizontal extent of subplots to 92% of their current width
  set(h, {'Position'}, mat2cell(vertcat(h.Position) .* [1 1 .92, 1], ones(size(h(:))),4))

[Jing Ci Neo]

It worked, thanks! I have another question regarding a sidebar function, cbarrow. Using cbarrow with tiled layout doesn't work at all, it erases the colorbar (see attached). Do you have any idea why that is happening?

Code

colormap(redblue)
h=colorbar('westoutside');
cbarrow

[Adam Danz]

This is a limitation with tiledlayout/nexttile method. This method has a lot more restrictions than the simpler approach, using subplot().

% tiledlayout(2,1)        % remove this
h(1) = subplot(2,1,1);    % use subplot
surf(peaks)
% Bottom plot
h(2) = (subplot(2,1,1))   % use subplot
surf(peaks * 2.5)

now you can use the cbarrow() function.

[Jing Ci Neo]

I see! Thanks

[Maximilian Grobbelaar]

I dont know why but this isn't working for me no matter what I try. I'm trying to have one colormap that spans over all subplots.

[Maximilian Grobbelaar]

[Adam Danz]

@Maximilian Grobbelaar Line color is not controlled by colormap. Instead, assign color directly using this approach:

numberOfLines = 4; 
colors = jet(numberOfLines); 

nexttile()
plot(___, 'Color', colors(1,:))

nexttile()
plot(___, 'Color', colors(2,:))

nexttile()
plot(___, 'Color', colors(3,:))

nexttile()
plot(___, 'Color', colors(4,:))