Make a scatter plot bigger and ad legend, axis

I have the following scatter plot, created from for loops. I want to make every staple as thick as possible, like so staple 1 and 2 are in contact with a contour seperating them. I also want a legend telling what the colors represent.. But I do not know how to make one

hold on

for y=1:2
xx=cell(length(AAG{y}),1);
I=cell(length(AAG{y}),1);
for o=1:length(AAG{y})
xx{o} =AAG{y}{o};
I{o}=AAI{y}(o);
end


for k1 = 1:length(AAG{y})
    scatter(ones(1,numel(xx{k1}))*y, xx{k1},ones(1,numel(xx{k1}))*I{k1})

end

end
xlim([0 3])

hold off