Plotting zero vectors in quiver3

Question

David Meixell 2020-12-3

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/675483-plotting-zero-vectors-in-quiver3

评论： KSSV 2020-12-3

I'm trying to plot the curl of the function v = -y + x + 0. This comes to (0,0,2), but I get an error stating the variables must be the same size, so I suspect the zeros are causing issues. How can I do a quiver3 plot with these numbers?

%% set up mesh
Xvc=(-5:2:5)';
Yvc=(-5:2:5)';
Zvc=(-5:2:5)';
[X,Y,Z]=meshgrid(Xvc, Yvc, Zvc);
%% plot V
Vx=-Y;           % Ex 2 Vx from worksheet
Vy=X;            % Ex 2 Vy from worksheet
Vz=0;            % Ex 2 Vz from worksheet
figure(110)
quiver3(X, Y, Z, Vx, Vy, Vz); %Changed to 2D plot due to lack of Vz values
grid on
xlabel('Vx')
ylabel('Vy')
%% compute curl
Crlx=0;         %Curl X from solved worksheet
Crly=0;         %Curl Y from solved worksheet
Crlz=2;         %Curl Z from solved worksheet
figure(120)
quiver(X, Y, Z, Crlx, Crly, Crlz);
grid on
tmp=0;

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Answer 1

KSSV 2020-12-3

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/675483-plotting-zero-vectors-in-quiver3#answer_563833

编辑：KSSV 2020-12-3

在 MATLAB Online 中打开

%% set up mesh

Xvc=(-5:2:5)';

Yvc=(-5:2:5)';

Zvc=(-5:2:5)';

[X,Y,Z]=meshgrid(Xvc, Yvc, Zvc);

%% plot V

Vx=-Y; % Ex 2 Vx from worksheet

Vy=X; % Ex 2 Vy from worksheet

Vz=zeros(size(X)); % Ex 2 Vz from worksheet

figure

quiver3(X, Y, Z, Vx, Vy, Vz); %Changed to 2D plot due to lack of Vz values

view(3)

grid on

xlabel('Vx')

ylabel('Vy')

●

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David Meixell 2020-12-3

在 MATLAB Online 中打开

Ah! So for the second part, if I change it to the following, it should work as well?

%% compute curl
Crlx=zeros(size(X));         %Curl X from solved worksheet = 0
Crly=zeros(size(X));         %Curl Y from solved worksheet = 0
Crlz=2*ones(size(X));      %Curl Z from solved worksheet = 2