Specify colour when using script ipvd.m

I am using the code attached (ipvd.m) to generate a progressive vector diagram for different data sets on the same figure.

How can I specify the colour of the line automatically (rather than using the plot editor manually) ?

My code calls the ipvd.m as follows:

figure
ipvd(uCurr5m/1000,vCurr5m/1000); 
hold on;
ipvd(uCurr15m/1000,vCurr15m/1000);
ipvd(uCurrspred/1000,vCurrspred/1000);
ipvd(uCurrbunn/1000,vCurrbunn/1000);

I tried the following (which did not work)

p = ipvd(uCurr5m/1000,vCurr5m/1000);
set(p,'color','r');

Any help would be greatly appreciated.

Jenny

Answer 1

[Matt Cohen]

Hi Jenny,

I understand that you are interested in automatically specifying and modifying the color of the line in the plot generated by the function "ipvd.m".

You can accomplish this task by making a minor modification to the function's code. In the last line of code in "ipvd.m", you should return the handle to the quiver object, as follows:

q = quiver(posX(1:n),posY(1:n),vx(:),vy(:),0);

Right now, this function does not appear to return any variables, even though you are treating it like it is. You should output this quiver object from the function:

function q = ipvd(vx,vy,xo,yo)

Just like other graphics objects in MATLAB, you can modify various property values through the quiver's handle. I have included a documentation link that provides information about the quiver series properties.

For example, the following code modifies the color of the quiver's line:

q = ipvd(1:10, 1:10);
q.Color = 'green';  % One syntax for modifying color
set(q,'Color','red');  % Another syntax

I hope this helps.

Matt