Clear Filters
Clear Filters

How to plot vectors exactly on the edge of another graph?

1 view (last 30 days)
The best I've got is expressed by the following:
clear
[u,v] = meshgrid(-2:0.2:2);
f = u.^2+v.^2-1;
[du,dv] = gradient(f);
hold all
g = @(a,b) a.^2+b.^2-1;
fimplicit(g)
D1 = u.^2+v.^2 >1;
D2 = u.^2+v.^2 <1.5;
v(~D1) = NaN;
u(~D2) = NaN;
norm = norm(gradient(f));
quiver(u,v,du./norm,dv./norm,'Color','r')
axis equal
However, the vectors are close to the edge, but not right originating from there. I can't think a straight way around it.

Accepted Answer

Matt J
Matt J on 15 Oct 2021
Edited: Matt J on 15 Oct 2021
t=linspace(0,360,91); t(end)=0;
u=cosd(t);
v=sind(t);
fimplicit(@(a,b) a.^2+b.^2-1);hold on
quiver(u,v,u,v,'Color','r'); hold off
axis equal
  1 Comment
Niklas Kurz
Niklas Kurz on 17 Oct 2021
Appreciated approch, using the outward second derivat of a circle parametrization.

Sign in to comment.

More Answers (0)

Categories

Find more on Vector Fields in Help Center and File Exchange

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!