George - a quick way to get text in (roughly) the centre of each square is to use the text function. Just append the following code to the end of your above code
% deltas for each x and y coordinate
dx = 1;
dy = 0.5;
% loop through each row of xb and yb
for k=1:size(xb,2)
for m=1:size(yb,2)
% add the value from data in roughly the centre of the square
text(xb(k)+ dx/2,yb(m)+dy/2,num2str(data(m,k)));
end
end
Running the above code will produce an image similar to what you have attached above (though it will be upside down). Try it and see what happens!
