Attempting to Plot In A Specific Range

Hello!

I am trying to plot some y-values in a specific range of x-values. I have x-values to -3.5 to 3.5 and should be increasing by one.

The y-values are all over the place, but I need all of them to be plotted. There are 45 values in the y vector.

I attempted to plot them using the following code...

x1 = [-3.5:3.5]

% y is a 45 x 1 single vector

plot(x1, y, '-')

However, when I do so, I get an error saying the vectors need to be the same length. What can I do to limit the y-vector to only contain values that fall in the x range?

Answer 1

[Torsten]

x1 = (linspace(-3.5,3.5,numel(y))).';
plot(x1,y,'-')

Answer 2

[Voss]

You will need a vector, the same length as y, containing an x value for each y value.

Let's say you have that vector and it's called x.

% Let's say this is your vector of x values
% (increasing by 1)
x = -21.5:22.5

x = 1×45

-21.5000 -20.5000 -19.5000 -18.5000 -17.5000 -16.5000 -15.5000 -14.5000 -13.5000 -12.5000 -11.5000 -10.5000 -9.5000 -8.5000 -7.5000 -6.5000 -5.5000 -4.5000 -3.5000 -2.5000 -1.5000 -0.5000 0.5000 1.5000 2.5000 3.5000 4.5000 5.5000 6.5000 7.5000

Then you can plot the points (x- and y-coordinates) where x is between -3.5 and 3.5 like this:

% (make up some random y)
y = rand(1,numel(x));

% limit the plot to those values of x between -3.5 and 3.5
idx = x >= -3.5 & x <= 3.5; % or idx = abs(x) <= 3.5;
plot(x(idx),y(idx))