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pythonmatplotlibnormalize

Quiver matplotlib : arrow with the same sizes

I'm trying to do a plot with quiver but I would like the arrows to all have the same size.

I use the following input :

q = ax0.quiver(x, y, dx, dy, units='xy' ,scale=1)

But even if add options like norm = 'true' or Normalize = 'true' the arrows are not normalized

Any one knows how to do this ? Thank you

Solution

  • Not sure if there is a way to do this by explicitly providing a kwarg to plt.quiver, but a quick work around would be like this:

    original plot

    x = np.arange(10)
y = np.arange(10)
xx, yy = np.meshgrid(x,y)
u = np.random.uniform(low=-1, high=1, size=(10,10))
v = np.random.uniform(low=-1, high=1, size=(10,10))
plt.quiver(xx, yy, u, v)

    original

    normalized plot

    r = np.power(np.add(np.power(u,2), np.power(v,2)),0.5) #could do (u**2+v**2)**0.5, other ways...
plt.quiver(xx, yy, u/r, v/r)

    enter image description here

    this just normalizes the u and v components of the vector by the magnitude of the vector, thereby maintaining the proper direction, but scaling down the magnitude of each arrow to 1