Merge pull request #1214 from ioam/mpl_interactive

Allow working with Renderers interactively outside the notebook

holoviews/plotting/mpl/__init__.py

@@ -1,12 +1,3 @@
-
-try:
-    # Switching to 'agg' backend (may be overridden in holoviews.rc)
-    import matplotlib.pyplot as plt
-    plt.switch_backend('agg')
-except:
-    pass
-
-
 import os
 from distutils.version import LooseVersion
 

holoviews/plotting/mpl/plot.py

@@ -119,6 +119,12 @@ def __init__(self, fig=None, axis=None, **params):
         if self.fig_latex:
             self.fig_rcparams['text.usetex'] = True
 
+        if self.renderer.interactive:
+            plt.ion()
+            self._close_figures = False
+        else:
+            plt.ioff()
+
         with mpl.rc_context(rc=self.fig_rcparams):
             fig, axis = self._init_axis(fig, axis)
 

holoviews/plotting/mpl/renderer.py

@@ -53,12 +53,15 @@ class MPLRenderer(Renderer):
         Output render multi-frame (typically animated) format. If
         None, no multi-frame rendering will occur.""")
 
+    interactive = param.Boolean(default=False, doc="""
+        Whether to enable interactive plotting allowing interactive
+        plotting with explicitly calling show.""")
+
     mode = param.ObjectSelector(default='default',
                                 objects=['default', 'mpld3', 'nbagg'], doc="""
          The 'mpld3' mode uses the mpld3 library whereas the 'nbagg' uses
          matplotlib's the experimental nbagg backend. """)
 
-
     # <format name> : (animation writer, format,  anim_kwargs, extra_args)
     ANIMATION_OPTS = {
         'webm': ('ffmpeg', 'webm', {},
@@ -112,6 +115,31 @@ def __call__(self, obj, fmt='auto'):
                       'mime_type':MIME_TYPES[fmt]}
 
 
+    def show(self, obj):
+        """
+        Renders the supplied object and displays it using the active
+        GUI backend.
+        """
+        if self.interactive:
+            if isinstance(obj, list):
+                return [self.get_plot(o) for o in obj]
+            return self.get_plot(obj)
+
+        from .plot import MPLPlot
+        MPLPlot._close_figures = False
+        try:
+            plots = []
+            objects = obj if isinstance(obj, list) else [obj]
+            for o in obj:
+                plots.append(self.get_plot(o))
+            plt.show()
+        except:
+            MPLPlot._close_figures = True
+            raise
+        MPLPlot._close_figures = True
+        return plots[0] if len(plots) == 1 else plots
+
+
     @classmethod
     def plot_options(cls, obj, percent_size):
         """
@@ -279,3 +307,11 @@ def validate(cls, options):
                                   "matplotlib:nbagg.\nSwitching widget mode to 'live'.")
             options['widgets'] = 'live'
         return options
+
+    @classmethod
+    def load_nb(cls, inline=True):
+        """
+        Initialize matplotlib backend
+        """
+        import matplotlib.pyplot as plt
+        plt.switch_backend('agg')