Plotting a diagram and getting some errors

Hi, I'm having an issue with my code. I'm trying to plot a basic diagram, but MATLAB is only giving me errors.Error massage is "

Undefined function 'plotv' for input arguments of type 'double'." I'm wondering where I might be going wrong. My code looks like this:

x_1 = [-0.9487 ; 0.3162];

x_2 = [-0.2425 ; -0.9701];

u = x_1 + x_2;

A_u = A .* u;

A_2u = A^2 * u;

hold on

plotv(x_1,'r');

plotv(x_2,'b');

plotv(u,'k');

plotv(A_u,'g');

plotv(A_2u,'c');

legend('x1','x2', 'u', 'Au', 'A^2u');

hold off

Answer 1

[VBBV]

There is no function called plotv in Matlab (or it must have been removed in new release), Please refer to the following link for plotting 2D graphs. Or use plotvec if you want to plot vectors

https://in.mathworks.com/help/matlab/ref/plot.html

x_1 = [-0.9487 ; 0.3162];
x_2 = [-0.2425 ; -0.9701];
u = x_1 + x_2;
A = randi([1 10]);
A_u = A .* u;
A_2u = A.^2 .* u;
hold on
plotvec(x_1,randi([0 4],1,4));
plotvec(x_2,randi([0 4],1,4));
plotvec(u,randi([0 4],1,4));
plotvec(A_u,randi([0 4],1,4));
plotvec(A_2u,randi([0 4],1,4));grid 
legend('x1','x2', 'u', 'Au', 'A^2u');
hold off

[Oskar S.]

Can I plot as vector ?

[VBBV]

If you want to plot vectors its better to use quiver, and apply your function

[X,Y] = meshgrid(linspace(-0.9487, 0.3162,10),linspace(-0.9701,-0.2425,10));
U = X+Y;
A = randi([1 10]).*U;
A2u = A.^2.*U;
hold on
quiver(X,Y,U,A,.5)
quiver(X,Y,U,A2u,1)

[Oskar S.]

thank you very much