Plotting X, Y cordintions with a line short line that indicates the angle

I have a Matrix (M) that looks like this:

X Y Angle

20 30 200

30 100 100

80 450 50

How can i plot a point for each raw as a coordinate? and a short line that indicates the angle/diraction this node is facing.

[darova]

What have you tried? Any ideas how to succeed?

[Ahmed Madhun]

Didn't find any tool usful yet. I saw some ideas, where i can use quiver(), but this require a transfrom of the angel to be set as u and v (which i didn't know that they represent)

Answer 1

[Kelly Kearney]

With quiver, the u and v arguments represent the horizontal and vertical components of the arrow you want to draw. You can calculate those easily based on the angle:

dat =[...
20          30       200
30         100       100
80         450        50];

u = cosd(dat(:,3));
v = sind(dat(:,3));

plot(dat(:,1), dat(:,2), 'o');
hold on;
s = 0.1; % scaling factor, adjust as desired
quiver(dat(:,1), dat(:,2), u, v, s);
axis equal;

[Ahmed Madhun]

That's exactly what i was looking for. Thanks!

Answer 2

[Neuropragmatist]

Your question is lacking some detail I suspect. Just to plot the XY data you could do this:

dat =[20         30        200
30         100        100
80         450        50];

figure
plot(dat(:,1),dat(:,2))

But my guess is that you are asking how you can plot lines starting at the XY coordinates with the angles listed in the third column? To do that you will have to choose a length of the lines and then you can do something like this:

% use dat from above
L = 100;
x2 = dat(:,1) + (L .* cosd(dat(:,3))); % use trigonometry to work out position of line 100 units from the starting point
y2 = dat(:,2) + (L .* sind(dat(:,3)));

figure
plot([dat(:,1) x2]',[dat(:,2) y2]')
daspect([1 1 1])

Hope this helps,

M.

[Ahmed Madhun]

Not really, i have a data set of coordinates (x and y) with represents a node. They also have a third variable which is the angle that i would like to represent, in order to see what this node is facing. i don't need to draw a full line between nodes, just something that can show me the direction of the node