MATLAB: How to create a quiver plot with logarithmic scaled arrows

MATLABquiver

Hey, I have a vector field with a large dynamic range; therefore the only way to properly see it in a quiver plot is if the length of the vectors will scale logarithmic instead of linearly.
As far as I know, there is no built in way to do it. Manually take the log before calling quiver will not work as it will change the angles, and therefore the quiver plot will be wrong.
I tried searching online but couldn't a way to do it, anyone knows one?
Another option is starting with the matlab built in quiver plot code and manually making another function that fixes it, is there anyway to get it?

Best Answer

I’m not certain what you’re plotting, so I’m guessing here.
This is one approach:
t = linspace(1E-3, 6*pi);
x = t .* cos(t) + 2; 
y = t.* sin(t) + 2;
dx = gradient(x);
dy = gradient(y);
figure(1)
quiver(x, y, dx, dy)                                        % Retain Scaling
grid
axis equal
log_dx = log(hypot(dx,dy)) .* (dx);
log_dy = log(hypot(dx,dy)) .* (dy);
figure(2)
quiver(x, y, log_dx, log_dy, 0)                             % Log Arrows, No Scaling
grid
axis equal
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