MATLAB: Annotations with arrows for scatter plot

arrowlabelsMATLABplotscatter

I have a scatter plot and would like to add labels with arrows for each data point (similar to the example below). I have a cellstring vector called ' labelc' with data labels of the same length as my x and y data vectors. I tried to use the annotation function in matlab to create the labels as follows…

a = annotation('textarrow',x,y,'String',labelc);

…but got an error message:

Error using annotation (line 121) unknown argument

Does anybody know how to achieve this?

Best Answer

*‘... with data labels of the same length as my x and y data vectors.’

That could be the problem. The documentation does not appear to support array arguments for them. See if putting the annotation calls in a loop, with one value for each ‘x’, ‘y’, and ‘labelc’ in every iteration works:

for k = 1:...
    a = annotation('textarrow',x(k),y(k),'String',labelc(k));
end

Make necessary changes to be certain ‘labelc’ is addressed correctly so it displays correctly.

(I am currently running a long optimization, and cannot test this approach just now.)

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MATLAB: How to plot 10 figures on same plot, and How do i find radius inbetween 0 and 1.

Try calling it like this where you pass in the x and y values from your arrays for the centers, and a random number between 0 and 1 for the radius:

for k = 1 : 10
    hold on;
    h(k) = Circle(x(k), y(k),rand(1))
end
hold off;

and take the holds out of Circle if you want 2 fewer lines.

MATLAB: Combination of textarrow and textbox

You could do the following:

xtip=0.5; ytip=0.5;   % arrow tip coordinates (normalized units)
w=0.15;      %box width
h=0.1;      %box height
offset=0.1;
str=['0.8042 p.u.' char(10) '15:05:20.133'];
x = [xtip-offset xtip];     % arrows start and end coordinates
y = [ytip+offset ytip];     % I've just offset by 0.1 in x and y. 
a=annotation('textarrow',x,y,'Color','red');
b=annotation('textbox',[xtip-w-0.1 ytip+0.1 w h],'String',str,'Color','red','EdgeColor','red');

The coordinates here are normalised with respect to your axes limits. For directly specifying coordinates w.r.t the data you used in the plot, like a point on your line, I would look at the following question.

Best Answer

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