How to plot velocity component

Hello All,

Can I plot y- velocity component in matlab I I have u,v and mesh? How?

Yashika

Answer 1

[KSSV]

Read about quiver.

https://www.mathworks.com/help/matlab/ref/quiver.html

[Yashika]

Hello,

Thank you but, I already read it, and it only said how to plot net velocity vectors using its component u and v. I want to plot only one out of it, x or y-velocity component. Either horizontal or vertical velocity conponents?

Yashika

[KSSV]

You can plot only one component as a colormap.....read about pcolor.

[Yashika]

Hello,

Thank you for the response, I read about pcolor and if I am not wrong, let (X,Y,V) are 3d matrix where X,Y is grid and V is magnitude of any quantity. Now, it appears pcolor plots as a surface of magnitude of that quantity.

All I want is arrows plot pointing in y-direction (as I am using only one directional component) with change in size with respect to its magnitude. Is this posible. If yes, kindly give some steps.

Yashika

[KSSV]

For that you can make one zero matrix of same size as X/Y/u/v and use quiver.

Let X , Y, u, v be your matrices.

O = zeros(size(X)) ; 
% x-components
figure
quiver(X,Y,u,O) ;
% y-components
figure
quiver(X,Y,O,v)

[Yashika]

Thank you so much for the trick.

Answer 2

[Yashika]

Hello KSSV,

I have one more question, how do I plot velocity interface on the top of quiver? I tried for contour but it say I need to have square matrix for the same. I have columns for xdata, ydata, Vx and Vy. I am attaching picture for the referance. I need to plot black line on each set of blue quivers out off this. I tried plot(x,Vx) it didn't plot single black curve for single set of blue arrow.

Yashika

[KSSV]

n = 10 ; 
x = zeros(n,1) ; 
y = (1:n)' ;
u = rand(n,1) ; 

v = zeros(n,1) ; 
h = quiver(x,y,u,v,'scale',0) ; 
hold on
plot(u,y,'b')

You need to play around with scale.