How to get rid of values from meshgrid

Question

esat gulhan 2020-9-21

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/597349-how-to-get-rid-of-values-from-meshgrid

评论： Ameer Hamza 2020-9-21

My code is below. I want to get rid of middle values of mesgrid which are very large. Nan maybe.

Is there any way to get rid of midle values (ı do not want see values in the midle of meshgrid ı want to blank [1 1] square from midle of meshgrid)

syms u uo ur v x y Q C r T tt 
V=100;b=2;uo=-V*sin(Q);ur=V*2*pi*b/(2.*pi.*r)+V*cos(Q);r=(x.^2+y.^2).^0.5;Q=atan2(y,x);
uo=subs(uo);ur=subs(ur);
%VECTORFIELD
[x,y] = meshgrid(-5:gl:5,-5:gl:5);
u=subs(ur*cos(Q)-uo*sin(Q));v=subs(ur*sin(Q)+uo*cos(Q));
quiver(x,y,u,v,1.01,'r','linewidth',2),grid on

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Ameer Hamza 2020-9-21

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/597349-how-to-get-rid-of-values-from-meshgrid#answer_497998

编辑：Ameer Hamza 2020-9-21

在 MATLAB Online 中打开

Try this

syms u uo ur v x y Q C r T tt 
V=100;b=2;uo=-V*sin(Q);ur=V*2*pi*b/(2.*pi.*r)+V*cos(Q);r=(x.^2+y.^2).^0.5;Q=atan2(y,x);
uo=subs(uo);ur=subs(ur);
%VECTORFIELD
gl = 0.11; % to avoid 0 in the meshgrid
[x,y] = meshgrid(-5:gl:5);
u=subs(ur*cos(Q)-uo*sin(Q));v=subs(ur*sin(Q)+uo*cos(Q));
mask = (abs(x) < 1) & (abs(y) < 1);
u(mask) = 0;
v(mask) = 0;
quiver(x,y,u,v,1.01,'r','linewidth',2),grid on