Merge pull request #1090 from pelson/external_transform_api

External transform api

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 +234,9 @@ 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

@@ -6022,7 +6022,7 @@ 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)
@@ -6550,7 +6550,7 @@ def stackplot(self, x, *args, **kwargs):
 
     def streamplot(self, x, y, u, v, density=1, linewidth=None, color=None,
                    cmap=None, norm=None, arrowsize=1, arrowstyle='-|>',
-                   minlength=0.1):
+                   minlength=0.1, transform=None):
         if not self._hold: self.cla()
         lines = mstream.streamplot(self, x, y, u, v,
                                    density=density,
@@ -6560,7 +6560,8 @@ def streamplot(self, x, y, u, v, density=1, linewidth=None, color=None,
                                    norm=norm,
                                    arrowsize=arrowsize,
                                    arrowstyle=arrowstyle,
-                                   minlength=minlength)
+                                   minlength=minlength,
+                                   transform=transform)
         return lines
     streamplot.__doc__ = mstream.streamplot.__doc__
 

lib/matplotlib/collections.py

@@ -156,9 +156,16 @@ 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 +199,7 @@ 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 +1414,7 @@ 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

@@ -774,6 +774,8 @@ 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()
 
@@ -822,6 +824,7 @@ 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)
@@ -841,6 +844,7 @@ 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)

lib/matplotlib/pyplot.py

@@ -3001,7 +3001,7 @@ def stackplot(x, *args, **kwargs):
         draw_if_interactive()
     finally:
         ax.hold(washold)
-
+    
     return ret
 
 # This function was autogenerated by boilerplate.py.  Do not edit as
@@ -3047,7 +3047,7 @@ def step(x, y, *args, **kwargs):
 @_autogen_docstring(Axes.streamplot)
 def streamplot(x, y, u, v, density=1, linewidth=None, color=None, cmap=None,
                norm=None, arrowsize=1, arrowstyle='-|>', minlength=0.1,
-               hold=None):
+               transform=None, hold=None):
     ax = gca()
     # allow callers to override the hold state by passing hold=True|False
     washold = ax.ishold()
@@ -3058,7 +3058,7 @@ def streamplot(x, y, u, v, density=1, linewidth=None, color=None, cmap=None,
         ret = ax.streamplot(x, y, u, v, density=density, linewidth=linewidth,
                             color=color, cmap=cmap, norm=norm,
                             arrowsize=arrowsize, arrowstyle=arrowstyle,
-                            minlength=minlength)
+                            minlength=minlength, transform=transform)
         draw_if_interactive()
     finally:
         ax.hold(washold)

lib/matplotlib/quiver.py

@@ -408,10 +408,11 @@ def __init__(self, ax, *args, **kw):
         self.width = kw.pop('width', None)
         self.color = kw.pop('color', 'k')
         self.pivot = kw.pop('pivot', 'tail')
+        self.transform = kw.pop('transform', ax.transData)
         kw.setdefault('facecolors', self.color)
         kw.setdefault('linewidths', (0,))
         collections.PolyCollection.__init__(self, [], offsets=self.XY,
-                                            transOffset=ax.transData,
+                                            transOffset=self.transform,
                                             closed=False,
                                             **kw)
         self.polykw = kw
@@ -529,8 +530,6 @@ def _angles_lengths(self, U, V, eps=1):
         lengths = np.absolute(dxy[:,0] + dxy[:,1]*1j) / eps
         return angles, lengths
 
-
-
     def _make_verts(self, U, V):
         uv = (U+V*1j)
         if self.angles == 'xy' and self.scale_units == 'xy':
@@ -592,7 +591,6 @@ def _make_verts(self, U, V):
 
         return XY
 
-
     def _h_arrows(self, length):
         """ length is in arrow width units """
         # It might be possible to streamline the code
@@ -824,6 +822,7 @@ def __init__(self, ax, *args, **kw):
         self.barb_increments = kw.pop('barb_increments', dict())
         self.rounding = kw.pop('rounding', True)
         self.flip = kw.pop('flip_barb', False)
+        transform = kw.pop('transform', ax.transData)
 
         #Flagcolor and and barbcolor provide convenience parameters for setting
         #the facecolor and edgecolor, respectively, of the barb polygon.  We
@@ -851,7 +850,7 @@ def __init__(self, ax, *args, **kw):
         #Make a collection
         barb_size = self._length**2 / 4 #Empirically determined
         collections.PolyCollection.__init__(self, [], (barb_size,), offsets=xy,
-            transOffset=ax.transData, **kw)
+            transOffset=transform, **kw)
         self.set_transform(transforms.IdentityTransform())
 
         self.set_UVC(u, v, c)

lib/matplotlib/streamplot.py

@@ -14,7 +14,7 @@
 
 def streamplot(axes, x, y, u, v, density=1, linewidth=None, color=None,
                cmap=None, norm=None, arrowsize=1, arrowstyle='-|>',
-               minlength=0.1):
+               minlength=0.1, transform=None):
     """Draws streamlines of a vector flow.
 
     *x*, *y* : 1d arrays
@@ -134,10 +134,15 @@ def streamplot(axes, x, y, u, v, density=1, linewidth=None, color=None,
             line_colors.extend(color_values)
             arrow_kw['color'] = cmap(norm(color_values[n]))
 
-        p = patches.FancyArrowPatch(arrow_tail, arrow_head, **arrow_kw)
+        p = patches.FancyArrowPatch(arrow_tail, 
+                                    arrow_head, 
+                                    transform=transform, 
+                                    **arrow_kw)
         axes.add_patch(p)
 
-    lc = mcollections.LineCollection(streamlines, **line_kw)
+    lc = mcollections.LineCollection(streamlines, 
+                                     transform=transform, 
+                                     **line_kw)
     if use_multicolor_lines:
         lc.set_array(np.asarray(line_colors))
         lc.set_cmap(cmap)