How to get back data from quiver function?
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Yuvarajendra Anjaneya Reddy
2023년 1월 8일
댓글: Yuvarajendra Anjaneya Reddy
2023년 1월 10일
Let's say I create a quiver plot with X, Y, U and V. If we think in the sense of particles, consider 'n' number of particles that particles have location [X,Y] and corresponding velocities [U, V]. The result from using 'quiver' function is, I get a vector plot that has vectors indicating direction and magnitude of particle displacement. This means that the particles have new locations [X1, Y1]. Is there a way to get this new location data?
I have checked the "get(hQ, 'Xdata')", function that gets me the original data that I have provided to the 'quiver' function, but I could not find the updated location data as inferred from the quiver plots.
I also, understand that scaling the arrows can have an impact on the new locations [X1, Y1]. But, that can not be a concern as of now. Any help is appreciated. Thanks in advance.
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채택된 답변
Adam Danz
2023년 1월 8일
편집: Adam Danz
2023년 1월 8일
> the particles have new locations [X1, Y1]. Is there a way to get this new location data?
If you already have the X, Y, U and V values, then the new location is
xnew = x+u;
ynew = y+v;
N.B. These coordinates will match the location of quiver arrow heads only when scaling is turned off.
Examples:
x = rand(1,20)*20 - 10;
y = rand(1,20)*10 + 40;
u = rand(1,20)*6 - 3;
v = rand(1,20)*10 - 5;
quiver(x,y,u,v,'off')
x1 = x + u;
y1 = y + v;
hold on
plot(x, y, 'bo') % mark arrow tail
plot(x1, y1, 'rs') % mark arrow head
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Adam Danz
2023년 1월 9일
In quiver(x,y,u,v), u and v are the horizontal and vertical components of the vector that starts at (x,y). You can use any units for u and v as long as they are consistent between u and v. For example, u and v could represent pressure or miles-per-3-hours instead of mph. Your choice of units affects how you interpret the magnitude (or length) of the resultant vector which shares the same units as U and V.
추가 답변 (1개)
MJFcoNaN
2023년 1월 8일
Hello,
The vector field is instantaneous, therefore, you have to provide the increment of time for getting a new proximate location. Or you can calculate it from a time series of vector fields.
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