How to add a single line to my plot??

I know it seems easy, but I'm having trouble doing this.

I basically need to plot horizontal lines with a length of 0.1m to the left and right of each of the points in my scatterplot.

After that, I need to allocate 2 vertical lines that connect the ends of the two horizontal lines I made previously, this way I would be making a kind of box, the boxplot function doesn't help me in this case, I need to do it this way, no matter how deoptimized or "brute" it is.

Answer 1

[Chunru]

Your specification is not clear and this is a guess.

x = 2*rand(10, 1);
y = 2*rand(10, 1);
scatter(x, y)
hold on
dx = 0.1;  dy = 0.1; 
for i=1:length(x)
    plot(x(i)+dx*[-1 1 1 -1 -1], y(i)+dy*[-1 -1 1 1 -1], 'r-');
end