Added jitter plot option for bokeh ScatterPlot

Author: philippjfr

holoviews/plotting/bokeh/chart.py

@@ -5,6 +5,7 @@
 from bokeh.models import (CategoricalColorMapper, CustomJS, HoverTool,
                           FactorRange, Whisker, Band, Range1d)
 from bokeh.models.tools import BoxSelectTool
+from bokeh.transform import jitter
 
 from ...core import Dataset, OrderedDict
 from ...core.dimension import Dimension
@@ -34,6 +35,9 @@ class PointPlot(LegendPlot, ColorbarPlot):
       Determines whether the `scaling_factor` should be applied to
       the width or area of each point (default: "area").""")
 
+    jitter = param.Number(default=None, bounds=(0, None), doc="""
+      The amount of jitter to apply to offset the points along the x-axis.""")
+
     scaling_factor = param.Number(default=1, bounds=(0, None), doc="""
       Scaling factor which is applied to either the width or area
       of each point, depending on the value of `scaling_method`.""")
@@ -91,6 +95,11 @@ def get_data(self, element, ranges, style):
         data.update(sdata)
         mapping.update(smapping)
 
+        if self.jitter:
+            axrange = 'y_range' if self.invert_axes else 'x_range'
+            mapping['x'] = jitter(dims[xidx], self.jitter,
+                                  range=self.handles[axrange])
+
         self._get_hover_data(data, element)
         return data, mapping, style