New to matlab, quick question about quiver

I'm trying to plot a simple vector field but I'm unsure of the syntax for quiver because it doesn't seem to be working. It's just displaying an empty plot

    % code
v = -5:0.1:5;
[x,y] = meshgrid(v);
u1=(2./x);
u2=(2.*y./(x.^2));
quiver(x,y,u1,u2)

Answer 1

[Star Strider]

They plot, but you have to turn off the scaling to see them. I’ll let you ponder how best to set their lengths, and perhaps set the axis limits as well. (You may have to narrow them significantly.)

To turn off scaling, set the scaling parameter to 0:

quiver(x,y,u1,u2,0)

[Kirby Fears]

Read the quiver() documentation for more info. Here's the section regarding the scale argument.

quiver(...,scale) automatically scales the arrows to fit within the grid and then stretches them by the factor scale. scale = 2 doubles their relative length, and scale = 0.5 halves the length. Use scale = 0 to plot the velocity vectors without automatic scaling. You can also tune the length of arrows after they have been drawn by choosing the Plot Edit tool, selecting the quiver object, opening the Property Editor, and adjusting the Length slider.

Answer 2

[Walter Roberson]

For me it shows a bunch of dots.

You have a scaling problem. Due to division by 0 your u1 runs from -20 to +infinity and your u2 runs from -infinity to +infinity.

You can get a slightly better plot if you use

u1(~isfinite(u1)) = nan;
u2(~isfinite(u2)) = nan;

and you can do even better if you confine u1 and u2 to smaller ranges, such as

u2 = min(max(u2,-20),20);

and just expand the size of your plot by dragging a corner of your figure to resize it.