Rotate a matplotlib Path object

问题

I'm using a matplotlib Path object to create a custom plotting marker as described here. I'd like to rotate the resulting path about its center by an arbitrary angle. Any suggestions on how to do this would be greatly appreciated.

Here's the code I'm using to create and plot the custom marker

import matplotlib.path
import matplotlib.pylab as plt

def getCustomMarker():

    verts = [( -5 , -15 ),
                ( -5 , -5 ),
                ( -15 , -5 ),
                ( -15 , 5 ),
                ( -5 , 5 ),
                ( -5 , 15 ),
                ( 5 , 15 ),
                ( 5 , 5 ),
                ( 15 , 5 ),
                ( 15 , -5 ),
                ( 5 , -5 ),
                ( 5 , -15 ),
                ( -5 , -15 )]

    verts = verts

    codes = [matplotlib.path.Path.MOVETO,
                matplotlib.path.Path.LINETO,
                matplotlib.path.Path.LINETO,
                matplotlib.path.Path.LINETO,
                matplotlib.path.Path.LINETO,
                matplotlib.path.Path.LINETO,
                matplotlib.path.Path.LINETO,
                matplotlib.path.Path.LINETO,
                matplotlib.path.Path.LINETO,
                matplotlib.path.Path.LINETO,
                matplotlib.path.Path.LINETO,
                matplotlib.path.Path.LINETO,
                matplotlib.path.Path.CLOSEPOLY]

    path = matplotlib.path.Path(verts, codes)

    return path

plt.scatter([0,0],[0,0], marker=getCustomMarker(), s=5000)
plt.show()

This is what I get:

This is the change I'd like to affect:

回答1:

You could call the transformed method on your path object with a rotational transform.

import matplotlib as mpl

marker = getCustomMarker()
marker = marker.transformed(mpl.transforms.Affine2D().rotate_deg(45))
plt.scatter([0,0],[0,0], marker=marker, s=5000)
plt.show()

回答2:

You could run the vertices list you have through a rotation matrix using an angle of 45 degrees to generate a new list of vertices. Something like this:

theta = 45. * pi / 180.
verts_rotated = [ (x * cos(theta) - y * sin(theta), x * sin(theta) + y * cos(theta)) for x,y in verts]

来源：https://stackoverflow.com/questions/48230875/rotate-a-matplotlib-path-object

标签

python

matplotlib

transformation