Heatmap - number of decimal places on x-axis

Hello everyone,

I've created a heatmap with x-axis values changing from 1.0 to 4.0 with the increment of 0.5. By default, these values are displayed on the x-axis as 1, 1.5, 2, 2.5 etc. Is there a way to change all of them to have one decimal place, i.e., 1.0, 1.5, 2.0, 2.5 etc.?

Answer 1

[Adam Danz]

Similar to Walter Roberson's answer but does not require undocumented methods (and avoids the associated warning).

h = heatmap(__);
h.XDisplayLabels = compose('%.1f',str2double(h.XDisplayLabels));

[M.G.]

It works! Thank you so much :)

[M.G.]

And do you know, maybe, how to make the same thing with the colorbar (added automatically) ticks?

[Walter Roberson]

I overlooked this!

[Adam Danz]

This is why I often recommend using imagesc() instead of heatmap where alterations like this are unnecessarily difficult. The only way to access the colorbar that I'm aware of, as of r2020b, is to use undocumented methods that will throw a warning.

h = heatmap(__);
S = struct(h);  % warning will appear
S.Colorbar.TickLabels = compose('%.1f', str2double(S.Colorbar.TickLabels));

[Adam Danz]

@Walter Roberson it's getting increasingly more difficult to remember all of the property names that essentially control the same components as other properties with the same name and this is especially true in the newer standalone visualization classes. XDisplayLabels in heatmap() is essentially the same as XTickLabel in virtually all other plotting functions. NumBins in scatterhistogram() is called NBins in scatterhist(). Grouped boxplots are created with boxplot(x,group) and uses 'symbol' to specify the outlier marker style but in boxchart groups are created with boxchart(group,x) and MarkerStyle is used to specify marker. I've come accross lots of these inconsistencies that develop a dependency on referencing the documentation.

Most of these inconsistencies should be fixed while allowing for backward compatibility; for example, 'NBins' could be documented while 'NumBins' could also be accepted.

[M.G.]

Thank you guys for your help. Now, my heatmap looks exactly like I wanted :)

Answer 2

[Walter Roberson]

https://www.mathworks.com/help/matlab/ref/xtickformat.html

'%.1f'

[M.G.]

Doesn't work with heatmap (see the screenshot below).

My experience with heatmaps tells me that for heatmaps everything is done differently than in the case of the other plots. That's why I started my topic highlighting it's about heatmap.

[Walter Roberson]

Unfortunately the function that constructs the details of the chart is in a .p file so I cannot check the details.

What I find is that the Heatmap object that is generated has a hidden object XAxis which is a CategoricalRuler .

h = heatmap(appropriate arguments);
hs = struct(h);      %a warning will be generated.
hs.XAxis.Categories = compose('%.1f', hs.XAxis.TickValues);  %assign new cell array of labels