def __init__( self, x, y, dx, dy, width=<NUM_LIT:1.0>, **kwargs ):
Patch.__init__(self, **kwargs)<EOL>L = np.sqrt(dx**<NUM_LIT:2>+dy**<NUM_LIT:2>) or <NUM_LIT:1> <EOL>cx = float(dx)/L<EOL>sx = float(dy)/L<EOL>trans1 = transforms.Affine2D().scale(L, width)<EOL>trans2 = transforms.Affine2D.from_values(cx, sx, -sx, cx, <NUM_LIT:0.0>, <NUM_LIT:0.0>)<EOL>trans3 = transforms.Affine2D().translate(x, y)<EOL>trans = trans1 + trans2 + trans3<EOL>self._patch_transform = trans.frozen()<EOL>
Draws an arrow, starting at (*x*, *y*), direction and length
given by (*dx*, *dy*) the width of the arrow is scaled by *width*.

Valid kwargs are:
%(Patch)s