How do I make my vector length even?

How would i make line x vectors to be even to the rest. To form three different lines on the graph. Also how do you make the points show up with like a circle, square and x.

x = linspace(5,(-2*pi),(2*pi));
x1 = linspace((-2*pi),(2*pi),10);
x2 = linspace((-2*pi),(2*pi),20);
y = sin(x);
axis([-6, 6, 0, 1])
plot(x,y, 'r')
hold on 
plot(x1,y, 'g')
hold on 
plot(x2,y, 'p')
title('Plot Comparison of sin(x)')
xlabel('x values')
ylabel('sin(x)')
legend('5 points','10 points','20 points')

Answer 1

[per isakson]

The statement

x = linspace(5,(-2*pi),(2*pi));

looks strange to me. On R2018b it creates a row vector of length 6, which suprises me. Did you mean

x = linspace((-2*pi),(2*pi),5);

The two statements

plot(x1,y, 'g')
plot(x2,y, 'p')

will throw errors, since the length of x1 and y differs. They are 10 and 6, respectively. And the length of x2 and y also differs.

"to be even to the rest" you can do that with interp1, 1-D data interpolation (table lookup)

"points show up with like a circle, square and x" with 'o', 's' and 'x', see plot, 2-D line plot (and browse the entire page)

[Kalpha.mc]

Yes the second one was what i did first but i changed it to see if i could make it work. and i also have to make a plot of three lines with 5 points 10 points and 20 points. I just can't seem to figure out how to get the vectors to be the same. ( Also the lines to have a square, circles and * for the points on the lines)

[per isakson]

I assume this is your homework. Am I right? Thus, I provide hints.

Regarding the markers, read the documentation on plot.

interp1 is most likely not what your teacher intended.

[Kalpha.mc]

Its not how she would want it but it's okay i already figured it out. Thank You!