Question

is there a simple way in Matlab to create visualisations like the following?

Important are the 2 ring-like shapes and the attached vectors, (more or less) pointing to the center of the black spots. Hints to other visualisation tools creating vector images which might lead to similar results are also very appreciated! All my efforts to solve that task did not bring me any further…

Matlab would be a good platform for automatically generating this kind of visualisation for different “spot-scenarios”…

Thank you in advance,
M.

Answer 1

Here’s part of the figure. The rest should be easy to figure out

%# define the ring
phi = linspace(0,2*pi,360);
innerRim = [cos(phi)',sin(phi)'];
outerRim = [cos(phi)',sin(phi)']*1.3;

xRing = [outerRim(:,1),innerRim(:,1),innerRim([2:end,1],1),outerRim([2:end,1],1)]';
yRing = [outerRim(:,2),innerRim(:,2),innerRim([2:end,1],2),outerRim([2:end,2],2)]';

%# create some data. 0 for black 0.5 for gray. 
%# RingData has a value for each degree
ringData = ones(1,360) * 0.5;
ringData(25:30) = 0;
ringData(77:80) = 0;
ringData(240:255) = 0;

%# plot the ring
%# for an outer ring, add 1 to xRing, yRing
figure
patch(xRing,yRing,ringData,'EdgeColor','none');
set(gca,'cLim',[0 1]);
axis square
axis off
set(gcf,'color','w');

%# plot three arrows at the origin
hold on, qh=quiver(zeros(3,1),zeros(3,1),[0.4;0.3;-0.5],[0.7;-0.1;0.3])
set(qh,'LineWidth',3)