How to add velocity colourbar to graph

Hey,

I have a 3D graph plotting the trajectory of a particle. My plot therefore provides the point to point position of the particle.

I was wondering if there was a method to add a color bar that represents the particle velocity at each position. I have the particle velocity at each position stored as vectors.

My plot is basically a curved line.Is there a way to use the colorbar command to enable the colour of the particle at each of the points to change correlating to the velocity?

Any help would be greatly appreciated :)

[Massimo Zanetti]

What command are you using to plot the curved line? Are you using plot3?

[Alexander Hamilton]

Yeah Im using plot3

Answer 1

[Massimo Zanetti]

The plot3 function does not allow to map different colors. However, you can get around using SURFACE. Try this.

%3d coordinates of a curve
x = 0:.05:2*pi;
y = sin(x);
z = cos(x);
%color vector: a set of values that are mapped in the colorbar
col = rand(1,numel(x)); 
%plot the curve as a surface
surface([x;x],[y;y],[z;z],[col;col],...
        'facecol','no',...
        'edgecol','interp',...
        'linew',2);
grid on; view([90,45,45]);
colorbar;

[Alexander Hamilton]

Thank you so much for your help!

[Massimo Zanetti]

Ok, so please accept this answer if it helped you. Max

Answer 2

[KSSV]

How about this?

N = 100 ;
% Take some positions 
x = linspace(0,2*pi,N) ;
y = sin(x) ;
%%associate some random velcoity 
v = rand(N,1) ;
hold on
plot(x,y,'r') ;  % plot trajcetory 
scatter(x,y,50,v,'filled') ; % velcoity as a scatter plot 
colorbar

[Alexander Hamilton]

Thank you for your help!