Simplify and generalize BezierSegment.

anntzer · anntzer · commit d6aae2f1c8fa · 2019-02-04T00:41:19.000+01:00
As it turns out, it is simpler to write the d-dimensional version than
the 2-dimensional special case.
diff --git a/examples/user_interfaces/embedding_in_wx4_sgskip.py b/examples/user_interfaces/embedding_in_wx4_sgskip.py
@@ -25,7 +25,7 @@ def __init__(self, canvas, cankill):
         # for simplicity I'm going to reuse a bitmap from wx, you'll
         # probably want to add your own.
         tool = self.AddTool(wx.ID_ANY, 'Click me', _load_bitmap('back.png'),
-                            'Activate custom contol')
+                            'Activate custom control')
         self.Bind(wx.EVT_TOOL, self._on_custom, id=tool.GetId())
 
     def _on_custom(self, evt):
diff --git a/lib/matplotlib/bezier.py b/lib/matplotlib/bezier.py
@@ -145,7 +145,7 @@ def find_bezier_t_intersecting_with_closedpath(
 
 class BezierSegment(object):
     """
-    A simple class of a 2-dimensional bezier segment
+    A D-dimensional Bezier segment.
     """
 
     # Higher order bezier lines can be supported by simplying adding
@@ -156,24 +156,21 @@ class BezierSegment(object):
 
     def __init__(self, control_points):
         """
-        *control_points* : location of contol points. It needs have a
-         shape of n * 2, where n is the order of the bezier line. 1<=
-         n <= 3 is supported.
+        Parameters
+        ----------
+        control_points : (N, D) array
+            Location of control points.  N = 2, 3 and 4 (linear, quadratic, and
+            cubic Beziers) are supported.
         """
         _o = len(control_points)
         self._orders = np.arange(_o)
-
         _coeff = BezierSegment._binom_coeff[_o - 1]
-        xx, yy = np.asarray(control_points).T
-        self._px = xx * _coeff
-        self._py = yy * _coeff
+        self._px = np.asarray(control_points).T * _coeff
 
     def point_at_t(self, t):
-        "evaluate a point at t"
-        tt = ((1 - t) ** self._orders)[::-1] * t ** self._orders
-        _x = np.dot(tt, self._px)
-        _y = np.dot(tt, self._py)
-        return _x, _y
+        """Return the point on the Bezier curve for parameter *t*."""
+        return tuple(
+            self._px @ (((1 - t) ** self._orders)[::-1] * t ** self._orders))
 
 
 @cbook._rename_parameter("3.1", "tolerence", "tolerance")
