quiver to show the magnitude of velocity

5 views (last 30 days)
Hi all,
I have the following:
w = sqrt(u^2+v^2);
now if I use quiver(x,y,u,v) and click on the arrow by cursor, I will have x and y along with velocities in x and y axis are going to be shown. I want to my cursor to show the magnitude of the velocity which is w. For that I have watched the following video and tried to do the same job.
Following is what I have done:
function moneyplot(x,y,u,v)
fh = figure;
dcm = datacursormode(fh);
datacursormode on
set(dcm, 'updatefcn', @myfunction)
function output_txt = myfunction(obj,event_obj,w)
pos = get(event_obj,'Position');
output_txt = {['velocity= ',w]};
if length(pos) > 2
output_txt{end+1} = ['Z: ',num2str(pos(3),4)];
However now every time I use the cursor to choose the arrow it shows : Error in custom datatip string function. Please see the picture below. What am I doing wrong?
Will be apreciated for any kinda input.

Accepted Answer

Changoleon on 25 Nov 2016
Edited: Changoleon on 25 Nov 2016
I did not find the answer to my question. Here is what I have done and it kinda works, better than nothing
x=[1 2 3 4 5];
y=[1 2 3 4 5];
u=[3 3 3 3 3];
v=[4 4 4 4 4];
for i = 1:5
[xx,yy] = ginput(2);
velocity=sqrt((xx(2)-xx(1))^2 + (yy(2)-yy(1))^2);
strmin = ['Velocity = ',num2str(velocity),' m/s',[1 1 1]];
t = text(xx(1),yy(1),strmin,'HorizontalAlignment','left');
s = t.FontSize;
t.FontSize = 12;

More Answers (0)


Find more on Vector Fields in Help Center and File Exchange

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!