plot - Vertical refline in matlab?

Question

How do I draw a vertical refline in matlab? e.g. I want to plot a line of x=5. Obviously using inf does not help at all. Can anyone give some advice?

Answer 1

You can create a vector with many identical values for x. Something like this:

x = 5*ones(1,100);
y = 1:100;
plot(x,y)

or use the line function:

line([5,5],[0,10])

To automatically detect the range of line, use ylim:

plot(1:10)

line([5,5],ylim)