Interesting problem!
This works, but it is restricted to the problem and the plot coordinates in your Question. You could generalise it to other problems, but I will leave that to you. The ‘coords’ vector I created to help me define where to put the text objects. I use the last two elements to determine where (coordinates) to plot them. The ‘S’ matrix is the array of counts, and simply sums the logical vector created by the conditional statements in it to create the counts for each quadrant. The documentation for patch explains how those work.
The axis call is an important part of the code because it defines the axis limits so that the patch objects display correctly.
Experiment with the colours of the patch objects, the marker colours, and the text object font to create the sort of plot you want.
The Code:
a = rand(10,1);
b = rand(10,1);
figure(1)
patch([0 0.5 0.5 0], [0 0 0.5 0.5],'y')
hold on
patch([0.5 1.0 1.0 0.5], [0 0 0.5 0.5],'g')
patch([0.5 1.0 1.0 0.5], [0.5 0.5 1.0 1.0],'b')
patch([0 0.5 0.5 0], [0.5 0.5 1.0 1.0],'r')
scatter(a, b, 'k')
hold off
axis([0 1 0 1])
for k1 = 1:2
for k2 = 1:2
S(k1,k2) = sum((a >= (k1-1)*0.5) & (a <= k1*0.5) & (b >= (k2-1)*0.5) & (b <= k2*0.5));
coords = [k1, k2, (k1-1)*0.5+0.25 (k2-1)*0.5+0.25];
text(coords(3), coords(4), sprintf('# = %2d', S(k1,k2)))
end
end
The Plot:
