Matlab：向量指定的x值处的垂直线

Question

I have a vector of x-values at which I would like to add vertical lines to a graph, say a row vector: vec = [1 2 3 4 5]

I know that you can add single vertical lines like this:

plot([1 1],[0 1])

(gives a vertical line at x=1 from y=0 to y=1).

But when I try something like

vec = [1 2 3 4 5]; lowLine = [0 0 0 0 0]; highLine = [1 1 1 1 1]; plot([vec vec],[lowLine highLine])

It does not give the required result, instead it gives a z-shape. Where am I going wrong?

Answer 1

In order to plot several lines in a single plot, you need to use the fact that MATLAB's plot function handles matrices as inputs, and that it sees each column of the inputs as different plots :

If X and Y are both matrices, then they must have equal size. The plot function plots columns of Y versus columns of X.

Thus, in order to get the expected result, you need to write :

vec = [1 2 3 4 5];
lowLine = [0 0 0 0 0];
highLine = [1 1 1 1 1];
plot([vec;vec],[lowLine;highLine])

Result :