- The arrow length is not normalized
- The arrows on the edge of the circular axes are cut off. The MATLAB Answers post at the following link provides a workaround for changing the circular axes radius: http://www.mathworks.com/matlabcentral/answers/102174-how-to-change-the-axis-limits-and-remove-alter-the-ticks-and-labels-for-a-compass-polar-plot
Adding an arrow to a polar plot
53 vues (au cours des 30 derniers jours)
Afficher commentaires plus anciens
Jelena Starovic
le 18 Déc 2015
Modifié(e) : Walter Roberson
le 9 Juin 2018
Is there any way to add an arrow to a polar plot? I want to show the orientation of a polar curve.
This is the curve that I am plotting:
t = 0:pi/100:2*pi;
r = abs((2+cos(t)).*(exp(2*1i*t)));
the = angle((2+cos(t)).*exp(2*1i*t));
polar(the,r)
0 commentaires
Réponse acceptée
Rebecca Krosnick
le 22 Déc 2015
There is not a single function or property in MATLAB that will allow you to add arrows to a polar plot to indicate orientation, but the following code will accomplish this. It uses the "quiver" function to display velocity vectors of the curve:
t = 0:pi/100:2*pi;
r = abs((2+cos(t)).*(exp(2*1i*t)));
the = angle((2+cos(t)).*exp(2*1i*t));
polar(the,r)
[X,Y] = pol2cart(the,r); % get Cartesian coordinates
factor = 5; % sampling ratio; factor=5 means the arrow will be drawn for every 5th point on the curve
i = 1; % index into quiver array
j = factor * factor; % index into X,Y Cartesian coordinates
u = []; % array for x component of quiver vector
v = []; % array for y component of quiver vector
xt = []; % array for x position of quiver vector
yt = []; % array for y position of quiver vector
while (j+1) <= length(X)
xt(i) = X(j);
yt(i) = Y(j);
u(i) = X(j+1) - X(j);
v(i) = Y(j+1) - Y(j);
i = i + 1;
j = i*factor;
end
hold on;
quiver(xt, yt, u, v);
A couple aspects of this code you may want to modify:
0 commentaires
Plus de réponses (0)
Voir également
Catégories
En savoir plus sur Vector Fields dans Help Center et File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!