Merge pull request matplotlib#1431 from pelson/transform_none

mdboom · mdboom · commit dd3d68e0bdf9 · 2012-10-30T05:55:01.000-07:00
Fixed transform=None behaviour on Artists.
diff --git a/lib/matplotlib/__init__.py b/lib/matplotlib/__init__.py
@@ -1066,6 +1066,7 @@ def tk_window_focus():
 
 default_test_modules = [
     'matplotlib.tests.test_agg',
+    'matplotlib.tests.test_artist',
     'matplotlib.tests.test_axes',
     'matplotlib.tests.test_backend_svg',
     'matplotlib.tests.test_backend_pgf',
diff --git a/lib/matplotlib/artist.py b/lib/matplotlib/artist.py
@@ -231,7 +231,7 @@ def set_transform(self, t):
         ACCEPTS: :class:`~matplotlib.transforms.Transform` instance
         """
         self._transform = t
-        self._transformSet = t is not None
+        self._transformSet = True
         self.pchanged()
 
     def get_transform(self):
@@ -240,7 +240,7 @@ def get_transform(self):
         instance used by this artist.
         """
         if self._transform is None:
-            self._transform = IdentityTransform()
+            self.set_transform(IdentityTransform())
         elif (not isinstance(self._transform, Transform)
               and hasattr(self._transform, '_as_mpl_transform')):
             self._transform = self._transform._as_mpl_transform(self.axes)
@@ -663,6 +663,7 @@ def update(self, props):
         store = self.eventson
         self.eventson = False
         changed = False
+            
         for k, v in props.iteritems():
             func = getattr(self, 'set_' + k, None)
             if func is None or not callable(func):
diff --git a/lib/matplotlib/streamplot.py b/lib/matplotlib/streamplot.py
@@ -65,6 +65,10 @@ def streamplot(axes, x, y, u, v, density=1, linewidth=None, color=None,
     mask = StreamMask(density)
     dmap = DomainMap(grid, mask)
 
+    # default to data coordinates
+    if transform is None:
+        transform = axes.transData
+
     if color is None:
         color = axes._get_lines.color_cycle.next()
 
diff --git a/lib/matplotlib/tests/test_artist.py b/lib/matplotlib/tests/test_artist.py
@@ -0,0 +1,81 @@
+from __future__ import print_function
+
+from matplotlib.testing.decorators import cleanup
+
+import matplotlib.pyplot as plt
+
+import matplotlib.patches as mpatches
+import matplotlib.transforms as mtrans
+import matplotlib.collections as mcollections
+
+
+@cleanup
+def test_patch_transform_of_none():
+    # tests the behaviour of patches added to an Axes with various transform
+    # specifications
+    
+    ax = plt.axes()
+    ax.set_xlim([1, 3])
+    ax.set_ylim([1, 3])
+    
+    #draw an ellipse over data coord (2,2) by specifying device coords
+    xy_data = (2, 2)
+    xy_pix = ax.transData.transform_point(xy_data)
+    
+    # not providing a transform of None puts the ellipse in data coordinates 
+    e = mpatches.Ellipse(xy_data, width=1, height=1, fc='yellow', alpha=0.5)
+    ax.add_patch(e)
+    assert e._transform == ax.transData
+    
+    # providing a transform of None puts the ellipse in device coordinates
+    e = mpatches.Ellipse(xy_pix, width=120, height=120, fc='coral', 
+                         transform=None, alpha=0.5)
+    ax.add_patch(e)
+    assert isinstance(e._transform, mtrans.IdentityTransform)
+    
+    # providing an IdentityTransform puts the ellipse in device coordinates
+    e = mpatches.Ellipse(xy_pix, width=100, height=100, 
+                         transform=mtrans.IdentityTransform(), alpha=0.5)
+    ax.add_patch(e)
+    assert isinstance(e._transform, mtrans.IdentityTransform)
+    
+
+@cleanup
+def test_collection_transform_of_none():
+    # tests the behaviour of collections added to an Axes with various 
+    # transform specifications
+
+    ax = plt.axes()
+    ax.set_xlim([1, 3])
+    ax.set_ylim([1, 3])
+    
+    #draw an ellipse over data coord (2,2) by specifying device coords
+    xy_data = (2, 2)
+    xy_pix = ax.transData.transform_point(xy_data)
+    
+    # not providing a transform of None puts the ellipse in data coordinates 
+    e = mpatches.Ellipse(xy_data, width=1, height=1)
+    c = mcollections.PatchCollection([e], facecolor='yellow', alpha=0.5)
+    ax.add_collection(c)
+    # the collection should be in data coordinates 
+    assert c.get_offset_transform() + c.get_transform() == ax.transData
+    
+    # providing a transform of None puts the ellipse in device coordinates
+    e = mpatches.Ellipse(xy_pix, width=120, height=120)
+    c = mcollections.PatchCollection([e], facecolor='coral', 
+                                     alpha=0.5)
+    c.set_transform(None)                          
+    ax.add_collection(c)
+    assert isinstance(c.get_transform(), mtrans.IdentityTransform)
+    
+    # providing an IdentityTransform puts the ellipse in device coordinates
+    e = mpatches.Ellipse(xy_pix, width=100, height=100)
+    c = mcollections.PatchCollection([e], transform=mtrans.IdentityTransform(), 
+                                     alpha=0.5)
+    ax.add_collection(c)
+    assert isinstance(c._transOffset, mtrans.IdentityTransform)
+    
+
+if __name__=='__main__':
+    import nose
+    nose.runmodule(argv=['-s','--with-doctest'], exit=False)
