Display Scale on Quiver Plot

Hello,

I'm looking to display the scale of my arrows on a quiver plot I've produced in relation to the plot itself. So the reader can look at my arrows and understand how they're size relate to the axis of the plot. I hope I'm being clear. Let me know if I'm not.

I basically don't know how to do this. Can anyone offer some suggestions or tips to make this happen.

Jack.

Answer 1

[Felipe Breton]

I had the same need, so what I did was to add one extra point in my map with a reference velocity. Then I added some text close to this "reference arrow" to explain it. Of course, some empty space on the map is needed. Basically, it would be as follows:

Taking the example shown in quiver.m 's reference page:

[x,y] = meshgrid(0:0.2:2,0:0.2:2);
u = cos(x).*y;
v = sin(x).*y;

figure

But then:

%An additional row of points  is added at y=2.2:
[X,Y]=meshgrid([0:0.2:2],2.2);

%Then a reference arrow velocity is defined at x=0.2 and y=2.2, while rest of points are left as zero:
u_rf=zeros(1,11);
v_rf=zeros(1,11);
u_rf(1,2)=1;

%Thus, quiver plot is applied including the new row:
quiver([X;x],[Y;y],[u_rf;u],[v_rf;v]); %is done like this to be sure we got the same arrow AutoScale

%Finally some text is included:
text(0.05,2.3,'Arrow scale: 1m/s')

Resulting in the following plot:

I hope it may help someone, as this post it quite old.

Felipe.

Answer 2

[Star Strider]

I never thought about doing that with quiver. I’m not certain that what you want to do is possible, but experiment with Quiver Series Properties, specifically those listed under ‘Arrow’.

[Jack B]

Oh okay, yeah because this plot is for a manuscript and showing a scale on the plot itself will allow the reader to understand the magnitude of the vectors.

I'll have a look at the properties thanks!

If anyone else has any other tips let me know!

Jack.

[Star Strider]

My pleasure!

The arrow lengths scale themselves, so I’m not certain exactly how you would display the scale on a legend or some such. I’ve never see this addressed anywhere, and I've never done it myself. I occasionally turned the 'AutoScale','off' to show the arrows for short segments (where the arrows might not otherwise be visible), but otherwise I just let them alone.

[kalani Lakshani]

Hello @Jack B

Can I know whether you found the answer for your question?