Support for transform in contour, and an external _as_mpl_transform api.

Author: pelson

lib/matplotlib/artist.py

@@ -3,7 +3,8 @@
 import matplotlib
 import matplotlib.cbook as cbook
 from matplotlib import docstring, rcParams
-from transforms import Bbox, IdentityTransform, TransformedBbox, TransformedPath
+from transforms import Bbox, IdentityTransform, TransformedBbox,
+                       TransformedPath, Transform
 from path import Path
 
 ## Note, matplotlib artists use the doc strings for set and get
@@ -223,7 +224,7 @@ def set_transform(self, t):
         ACCEPTS: :class:`~matplotlib.transforms.Transform` instance
         """
         self._transform = t
-        self._transformSet = True
+        self._transformSet = t is not None
         self.pchanged()
 
     def get_transform(self):
@@ -233,6 +234,8 @@ def get_transform(self):
         """
         if self._transform is None:
             self._transform = IdentityTransform()
+        elif not isinstance(self._transform, Transform) and hasattr(self._transform, '_as_mpl_transform'):
+            self._transform = self._transform._as_mpl_transform(self.axes)
         return self._transform
 
     def hitlist(self, event):

lib/matplotlib/axes.py

@@ -5965,7 +5965,7 @@ def scatter(self, x, y, s=20, c='b', marker='o', cmap=None, norm=None,
                 edgecolors = edgecolors,
                 linewidths = linewidths,
                 offsets = zip(x,y),
-                transOffset = self.transData,
+                transOffset = kwargs.pop('transform', self.transData),
                 )
         collection.set_transform(mtransforms.IdentityTransform())
         collection.set_alpha(alpha)

lib/matplotlib/collections.py

@@ -156,9 +156,15 @@ def set_paths(self):
     def get_transforms(self):
         return self._transforms
 
+    def get_offset_transform(self):
+        t = self._transOffset
+        if not isinstance(t, transforms.Transform) and hasattr(t, '_as_mpl_transform'):
+            t = t._as_mpl_transform(self.axes)
+        return t
+
     def get_datalim(self, transData):
         transform = self.get_transform()
-        transOffset = self._transOffset
+        transOffset = self.get_offset_transform()
         offsets = self._offsets
         paths = self.get_paths()
 
@@ -192,7 +198,7 @@ def _prepare_points(self):
         """Point prep for drawing and hit testing"""
 
         transform = self.get_transform()
-        transOffset = self._transOffset
+        transOffset = self.get_offset_transform()
         offsets = self._offsets
         paths = self.get_paths()
 
@@ -1407,7 +1413,7 @@ def draw(self, renderer):
         if not self.get_visible(): return
         renderer.open_group(self.__class__.__name__, self.get_gid())
         transform = self.get_transform()
-        transOffset = self._transOffset
+        transOffset = self.get_offset_transform()
         offsets = self._offsets
 
         if self.have_units():

lib/matplotlib/contour.py

@@ -772,6 +772,8 @@ def __init__(self, ax, *args, **kwargs):
             raise ValueError('Either colors or cmap must be None')
         if self.origin == 'image': self.origin = mpl.rcParams['image.origin']
 
+        self.transform = kwargs.get('transform', None)
+
         self._process_args(*args, **kwargs)
         self._process_levels()
 
@@ -820,6 +822,7 @@ def __init__(self, ax, *args, **kwargs):
                                      antialiaseds = (self.antialiased,),
                                      edgecolors= 'none',
                                      alpha=self.alpha,
+                                     transform=self.transform,
                                      zorder=zorder)
                 self.ax.add_collection(col)
                 self.collections.append(col)
@@ -839,6 +842,7 @@ def __init__(self, ax, *args, **kwargs):
                                      linewidths = width,
                                      linestyle = lstyle,
                                      alpha=self.alpha,
+                                     transform=self.transform,
                                      zorder=zorder)
                 col.set_label('_nolegend_')
                 self.ax.add_collection(col, False)