How to display colorbar label with App Designer

Hi,

I'm trying to display the colorbar label in an axis from App Designer but the text goes outside the limits and is not properly displayed as shown below:

The code I'm usig:

c = colorbar(app.UIAxes)
colormap(app.UIAxes, jet)
c.Label.String = 'Example Color Label';

How can I properly display the label?

Thanks.

Answer 1

[Yogesh Khurana]

Hi,

You can try editing axes font size to a value less than the default value that is 12. If you change the axes font size, then MATLAB automatically sets the font size of the colorbar to 90% of the axes font size. I have written the following code to change axes font size:

c = colorbar(app.UIAxes); 
colormap(app.UIAxes, jet); 
c.Label.String = 'Example Color Label'; 
app.UIAxes.FontSize = 10; 

The output of above code is:

Another way is to set the position of colorbar manually using Position property of colorbar.

You can also refer to documentations of Axes properties and Colorbar properties:

Axes Properties: https://www.mathworks.com/help/matlab/ref/matlab.graphics.axis.axes-properties.html

Colorbar Properties:

https://www.mathworks.com/help/matlab/ref/matlab.graphics.illustration.colorbar-properties.html

[Marco Furlan]

Thanks

[Chris Oreinos]

I am suprised by two things here; (1) that this ad-hoc workaround was given as an official answer by MathWorks Staff, and (2), that this reply was accepted as an "answer".

So, the offerred "solution" maybe works in some cases. It is not universal. However, colorbar formatting should work out-of-the-box! As of R2019a versions, it only works for figures/axes but NOT for uifigures/uiaxes. Try it yourselves:

% Colorbar label appears fine
hFig = figure;
hAxes = axes(hFig);
imagesc(hAxes, magic(5))
hClr = colorbar(hAxes);
hClr.Label.String = 'Magic numbers';

% Colorbar label is cropped
hFig = uifigure;
hAxes = uiaxes(hFig);
imagesc(hAxes, magic(5))
hClr = colorbar(hAxes);
hClr.Label.String = 'Magic numbers';

Mathworks seems to be promoting the transition to App-designer (as opposed to the old GUIDE), which goes hand-in-hand with the replacement of figure/axes by uifigures/uiaxes. However, it hasn't even tested its built-in functions against the new framework. Let alone provide the customization possible in the "old" figures/axes world.

Please provide a real solution to the cropped colorbar labels. Also, the ability to have the label on top of the colorbar, as was the case in older MATLAB versions (by using the XLable property of the underlying colorbar axes), is something that should also be provided now.

[Pierre Lebel]

I agree with Chris

[Chris Oreinos]

I contacted the Mathwors support and was given the following 2, still not-satisfying workarounds:

% Workaround #1
% Move the colorbar y axis label to the left.
hFig = uifigure;
hAxes = uiaxes(hFig);
imagesc(hAxes, magic(5))
hClr = colorbar(hAxes);
hClr.Label.String = 'Magic numbers';
hClr.AxisLocation = 'in';
 
% Workaround #2
% Expand the width of the outer position of the axes a bit
hFig = uifigure;
hAxes = uiaxes(hFig);
imagesc(hAxes, magic(5))
hClr = colorbar(hAxes);
hClr.Label.String = 'Magic numbers';
hAxes.OuterPosition(3) = 500; % Change this value to fit your needs

On a positive note though, they confirmed that this is a known bug for their development team. Nonetheless, there was no time frame for solving that bug.

[Jan S]

I have the same Problem now. Using the Colorbar with "eastoutside" will lead to a half cutted Colorbar-Label. All other possibilities (north, west, south and inside) aren't really helpfull, because there are axis-Labels and titles from the graph.

I try to use a X-Label for the Colorbar instead which worked well - until i implement the oportunity to switch between a linear and log scale for the colorbar. If i change to log scale, the XLabel will disappear completely. Another Bug maybe? This only works for linear scale.

To the proposed solution from matlab:

Switch the Colorbar-axis-location inside isn't a helpfull solution since it will overlap with the image/graph. Working with resizing in a dynamic app with grid structure is also impossible.

If anybody has a good solution, it would be nice, of he/she can share it until the bug isn't fixed.