plot several X=const

Hello,

I have a vector G (with 120 values).

I'd like to plot a vertical line for each value of this vector in a graph having an other curve. How can I do this?

thank you

Answer 1

[Image Analyst]

Perhaps the stem() function?

g = rand(1, 10);
plot(g, 'ro-', 'LineWidth', 2);
hold on;
stem(g);

[José-Luis]

x = 1:100;
y =  cos(x .* 2 .* pi ./100);

X = rand(1,10) .* 100;
Y = interp1(x,y,X);

plot(x,y,'r-','Marker','*');
hold on
stem(X,Y)

[Image Analyst]

Maxime's "Answer" moved here since it's not an answer to her original question:

ok, thank but it is not that I want exactely:

I mean:

I have a Y vector comprising a set of values (eg Y = (2.5, 34, 65, -12, etc ...) I have another G vector comprising a set of values (eg G = (12.5, 5.789, 4.6102, 21.09, etc ...).

I would like to draw on the same graph the curve defined by the vector Y, and, the vertical lines of equation X = 12.5, X = 5.789, X = 4.6102, X = X 21.09 = ... etc (the values defined by my G vector...

How can I do ?

!!!! Y and G have not the same length

[Image Analyst]

How about this:

Y = [2.5, 34, 65, -12]
G = [12.5, 5.789, 4.6102, 21.09]
plot(Y, 'ro-', 'LineWidth', 4);
grid on;
hold on;
stem(G, max(Y)*ones(1, length(G)), 'Marker', 'none', 'LineWidth', 4);

Note: Y and G don't have to have the same number of elements. ALso, you have not defined an X for the Y values so I'm just assuming X is the index number. For the "G" lines, I'm having them go just from 0 up to the max Y value since you gave no indication of where the lines start or stop.

[Image Analyst]

Another option to go the full height of the graph is to use line() function:

Y = [2.5, 34, 65, -12]
G = [12.5, 5.789, 4.6102, 21.09]
plot(Y, 'ro-', 'LineWidth', 4);
grid on;
hold on;
yl = ylim();
for k = 1 : length(G)
  x = G(k);
  line([x, x], yl, 'Marker', 'none', 'LineWidth', 4);
end