ENH: rects with infinite coordinates

closes #166

doc/changelog.rst

@@ -183,6 +183,9 @@ Enhancements
 - You can now use a ``dict`` (with manual scales) to map data values to
   aesthetics (:issue:`169`).
 
+- You can now specify infinite coordinates with :class:`plotnine.geoms.geom_rect`
+  (:issue:`166`)
+
 Bug Fixes
 *********
 

plotnine/geoms/geom_rect.py

@@ -3,6 +3,7 @@
 
 from matplotlib.collections import PolyCollection
 from six.moves import zip
+import numpy as np
 
 from ..utils import to_rgba, SIZE_FACTOR
 from ..doctools import document
@@ -39,6 +40,15 @@ def draw_group(data, panel_params, coord, ax, **params):
         data = coord.transform(data, panel_params, munch=True)
         data['size'] *= SIZE_FACTOR
         verts = [None] * len(data)
+
+        # Make it easy to specify rects that fill the x|y range
+        xlimits = panel_params['x_range']
+        ylimits = panel_params['y_range']
+        data['xmin'].replace(-np.inf, xlimits[0], inplace=True)
+        data['xmax'].replace(np.inf, xlimits[1], inplace=True)
+        data['ymin'].replace(-np.inf, ylimits[0], inplace=True)
+        data['ymax'].replace(np.inf, ylimits[1], inplace=True)
+
         limits = zip(data['xmin'], data['xmax'],
                      data['ymin'], data['ymax'])
 

plotnine/tests/test_geom_rect_tile.py

@@ -1,8 +1,9 @@
 from __future__ import absolute_import, division, print_function
 
 import pandas as pd
+import numpy as np
 
-from plotnine import ggplot, aes, geom_rect, geom_tile, labs, theme
+from plotnine import ggplot, aes, geom_point, geom_rect, geom_tile, labs, theme
 
 n = 4
 
@@ -72,3 +73,27 @@ def test_tile_aesthetics():
          _theme)
 
     assert p == 'tile-aesthetics'
+
+
+def test_infinite_rects():
+    df = pd.DataFrame({
+        'x': range(10),
+        'y': range(10)
+    })
+    rdf = pd.DataFrame({
+        'xmin': [3],
+        'xmax': 7,
+        'ymin': -np.inf,
+        'ymax': np.inf,
+    })
+
+    p = (ggplot(df, aes('x', 'y'))
+         + geom_point()
+         + geom_rect(
+             data=rdf,
+             mapping=aes(xmin='xmin', xmax='xmax', ymin='ymin', ymax='ymax'),
+             alpha=0.2,
+             inherit_aes=False)
+         )
+
+    assert p == 'infinite-rects'