How can I change the color of a circle according to a changing variable?

For my thesis I will calculate a certain parameter in real-time. This parameter will be updated every 10s using a timer. Now I would like to use the changing value of this parameter to give the test person feedback. I was thinking of doing this by having a dark backround with a filled circle in the middel of the screen. This circle should change color according to the performance of the subject.

So far I had the following idea:

x = [0 0 1 1 0];

y = [0 1 1 0 0];

h = fill(x,y,[0.2, 0.2, 0.2])

hold on

rectangle('Position', [0.4 0.4 0.2 0.2], 'Curvature', [1 1], 'FaceColor', [x 1-x 0]) % with x = parameter

axis off

Problems with this is that I would realy like for the full screen would be used. So I don't want to see the matlab figure in the figure window anymore. How could I do this?

Another problem is that my circle no longer looks like a circle when I maximize the window. (Because my computer screen isn't square.) Does anybody have an idea on how I could solve this?

Other suggestions for better plots of visualisations would be very much appreciated!

The goal is that the participant gets a color coded feedback on how well he is doing e.g. green = good, red = bad, orange = something in between,...

Answer 1

[Baltam]

Hi fellow Belgian,

Look at the following code and the provided comments

x = [0 0 1 1 0];
y = [0 1 1 0 0];
% 'name' and 'numbertitle' to remove 'figure 1' and replace it with
% 'Performance'. 'outerposition' and 'unit' to go "full screen". 'color' to
% make white background'. 'menubar' to hide the menubar. 
hfig = figure('name','Performance','numbertitle','off','unit','normalized','outerposition',[0 0 1 1],'Color',[1 1 1],'menubar','none');

% loop over x for example
for i =1:numel(x)

      rectangle('Position', [0.0 0.0 1 1], 'Curvature', [1 1], 'FaceColor', [x(i) 1-x(i) 0]) % with x = parameter

      ax = gca; 
      % remove tick labels
      set(ax,'XTick',[]),set(ax,'YTick',[])
      % make lines of the axes white --> invisible on white background
      set(ax,'XColor',[1,1,1]) , set(ax,'YColor',[1,1,1]) 
      % make axes square to get round circle
      axis square
      pause(0.5)
  end

Kind regards, Baltam

[Annelies Baptist]

Thank you! This certainly helps :-)