Class Ellipse

lib/matplotlib/patches.py:1701–1878

A scale-free ellipse.

class Ellipse(Patch):
    """A scale-free ellipse."""

    def __str__(self):
        pars = (self._center[0], self._center[1],
                self.width, self.height, self.angle)
        fmt = "Ellipse(xy=(%s, %s), width=%s, height=%s, angle=%s)"
        return fmt % pars

    @_docstring.interpd
    def __init__(self, xy, width, height, *, angle=0, **kwargs):
        """
        Parameters
        ----------
        xy : (float, float)
            xy coordinates of ellipse centre.
        width : float
            Total length (diameter) of horizontal axis.
        height : float
            Total length (diameter) of vertical axis.
        angle : float, default: 0
            Rotation in degrees anti-clockwise.

        Notes
        -----
        Valid keyword arguments are:

        %(Patch:kwdoc)s
        """
        super().__init__(**kwargs)

        self._center = xy
        self._width, self._height = width, height
        self._angle = angle
        self._path = Path.unit_circle()
        # Required for EllipseSelector with axes aspect ratio != 1
        # The patch is defined in data coordinates and when changing the
        # selector with square modifier and not in data coordinates, we need
        # to correct for the aspect ratio difference between the data and
        # display coordinate systems.
        self._aspect_ratio_correction = 1.0
        # Note: This cannot be calculated until this is added to an Axes
        self._patch_transform = transforms.IdentityTransform()

    def _recompute_transform(self):
        """
        Notes
        -----
        This cannot be called until after this has been added to an Axes,
        otherwise unit conversion will fail. This makes it very important to
        call the accessor method and not directly access the transformation
        member variable.
        """
        center = (self.convert_xunits(self._center[0]),
                  self.convert_yunits(self._center[1]))
        width = self.convert_xunits(self._width)
        height = self.convert_yunits(self._height)
        self._patch_transform = transforms.Affine2D() \