Set default figure size in inline mode to (6,4).

Otherwise, unless users have configured it manually, the default of
(8, 6) that mpl uses produces giant figures on the canvas that aren't
particularly useful.

Since controlling the figure size in inline mode may be a more
frequent need, added a top-level helper (most people won't know what
the right call is to make otherwise).

IPython/lib/pylabtools.py

@@ -109,8 +109,14 b' def import_pylab(user_ns, backend, import_all=True, shell=None):'
         # function that will pick up the results for display.  This can only be
         # done with access to the real shell object.
         if backend == backends['inline']:
-            from IPython.zmq.pylab.backend_inline import flush_svg
+            from IPython.zmq.pylab.backend_inline import flush_svg, figsize
+            from matplotlib import pyplot
             shell.register_post_execute(flush_svg)
+            # The typical default figure size is too large for inline use.  We
+            # might make this a user-configurable parameter later.
+            figsize(6.0, 4.0)
+            # Add 'figsize' to pyplot and to the user's namespace
+            user_ns['figsize'] = pyplot.figsize = figsize
         else:
             from IPython.zmq.pylab.backend_inline import pastefig
             from matplotlib import pyplot

IPython/zmq/pylab/backend_inline.py

@@ -38,6 +38,16 b' def show(close=True):'
 show._draw_called = False
 
 
+def figsize(sizex, sizey):
+    """Set the default figure size to be [sizex, sizey].
+
+    This is just an easy to remember, convenience wrapper that sets::
+
+      matplotlib.rcParams['figure.figsize'] = [sizex, sizey]
+    """
+    matplotlib.rcParams['figure.figsize'] = [sizex, sizey]
+    
+
 def pastefig(*figs):
     """Paste one or more figures into the console workspace.
 
@@ -68,9 +78,6 b' def pastefig(*figs):'
 def send_svg_canvas(canvas):
     """Draw the current canvas and send it as an SVG payload.
     """
-    # Make the background transparent.
-    # figure_manager.canvas.figure.patch.set_alpha(0.0)
-
     # Set the background to white instead so it looks good on black.  We store
     # the current values to restore them at the end.
     fc = canvas.figure.get_facecolor()