Jakob,
This is a necessarily, I think, imprecise process. That is, this method may become invalid with later distributions of Matlab. I have found that the labels in your particular situation start with two spaces. This is a quite volatile piece of information to use, but it gets the job done. Here is my code to setup the labels.
% Get figure and axes
fHand = figure;
aHand = axes('parent', fHand);
% Make sure limits are correct.
pHand = polar(0, 2, 'parent', aHand);
delete(pHand)
% Get the handles of interest (using volatile info above).
hands = findall(fHand,'parent', aHand, 'Type', 'text');
hands = hands(strncmp(' ', get(hands,'String'), 2));
hands = sort(hands);
% Relabel from inside out.
labels = {'label one', 'label two', 'label three', 'label four'}
for i = 1:4
set(hands(i),'String', labels{i})
end
% Make sure to 'hold on' to keep your labels before plotting.
hold on
t = 0:.01:2*pi; polar(t,4*sin(2*t).*cos(2*t),'--r', 'parent', aHand);
I hope this helps.
~Jonathan
