MATLAB: Display comma instead of dot at contour levels

clabelcomma for dotcontour labelscontour plotMATLAB

Hello everyone,

the title is basically my whole question. I want to change the labels on the contour levels of a contour plot so that the numbers have a comma instead of a dot (its a german thing).

I've read that following code would have worked in older versions of Matlab – C and h being the outputs of the contour function:

acl=clabel(C,h,'FontSize',10,'Color','k');
for i=1:length(acl) 
oldlabel=get(acl(i), 'String'); 
newlabel=strrep(oldlabel, '.', ','); 
set(hcl(i),'String',newlabel); 
end

In the Matlab version I'm using, clabel is returning a "GraphicsPlaceholder"-Object, which I cannot change in the same way. How would I change the labels in Matlab version R2017a ?

(Same question has been posted here in german)

Best Answer

Yair recently posted some details on customizing contour lines and labels. See https://undocumentedmatlab.com/blog/customizing-contour-plots-part2

Related Solutions

MATLAB: How to change the labels values under contour plot (CONTOUR and CLABEL)

Turns out if you do not pass the contour handle to clabel, then clabel outputs the labels, which you can easily change. If you instead add the contour handle, then the labels are stored in the contour handle's hidden property 'TextPrism'.

Here's an example where the labels are increased by a factor of two using the hidden property:

[C,hContour]=contourf(peaks)
clabel(C,hContour)
drawnow
labels=hContour.TextPrims
for idx = 1 : numel(labels)
    LabelValue=str2num(labels(idx).String);
    NewValue=LabelValue*2;
    hContour.TextPrims(idx).String=num2str(NewValue)
end

MATLAB: How to label a contour plot in the same colors as the contour lines

There is no need to use Java, just to use the two hidden (undocumented/unsupported) properties TextPrims (the text label handles) and EdgePrims (the contour line handles), as shown below. For additional info on customizing the contour labels/lines/faces read https://undocumentedmatlab.com/blog/customizing-contour-plots

% Create a simple contour plot
x = -2:0.2:2;
y = -2:0.2:3;
[X,Y] = meshgrid(x,y);
Z = X.*exp(-X.^2-Y.^2);
[C,hContour] = contour(X,Y,Z, 'ShowText','on');
% Update the text label colors
levels = hContour.LevelList;
labels = hContour.TextPrims;  % undocumented/unsupported

lines  = hContour.EdgePrims;  % undocumented/unsupported
for idx = 1 : numel(labels)
   labelValue = str2num(labels(idx).String);
   lineIdx = find(abs(levels-labelValue)<3*eps, 1); %avoid FP errors using eps
   labels(idx).ColorData = lines(lineIdx).ColorData;
end

Best Answer

Related Solutions

MATLAB: How to change the labels values under contour plot (CONTOUR and CLABEL)

MATLAB: How to label a contour plot in the same colors as the contour lines

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