Merge pull request #807 from parulsethi/dendrogram_annotation

Add annotation parameter for dendrogram

Author: jackparmer

Diff for: plotly/figure_factory/_dendrogram.py

@@ -16,7 +16,8 @@
 
 def create_dendrogram(X, orientation="bottom", labels=None,
                       colorscale=None, distfun=None,
-                      linkagefun=lambda x: sch.linkage(x, 'complete')):
+                      linkagefun=lambda x: sch.linkage(x, 'complete'),
+                      hovertext=None):
     """
     BETA function that returns a dendrogram Plotly figure object.
 
@@ -28,6 +29,7 @@ def create_dendrogram(X, orientation="bottom", labels=None,
                                the observations
     :param (function) linkagefun: Function to compute the linkage matrix from
                                   the pairwise distances
+    :param (list[list]) hovertext: List of hovertext for constituent traces of dendrogram
 
         clusters
 
@@ -85,7 +87,8 @@ def create_dendrogram(X, orientation="bottom", labels=None,
         distfun = scs.distance.pdist
 
     dendrogram = _Dendrogram(X, orientation, labels, colorscale,
-                             distfun=distfun, linkagefun=linkagefun)
+                             distfun=distfun, linkagefun=linkagefun,
+                             hovertext=hovertext)
 
     return graph_objs.Figure(data=dendrogram.data, layout=dendrogram.layout)
 
@@ -96,7 +99,8 @@ class _Dendrogram(object):
     def __init__(self, X, orientation='bottom', labels=None, colorscale=None,
                  width="100%", height="100%", xaxis='xaxis', yaxis='yaxis',
                  distfun=None,
-                 linkagefun=lambda x: sch.linkage(x, 'complete')):
+                 linkagefun=lambda x: sch.linkage(x, 'complete'),
+                 hovertext=None):
         self.orientation = orientation
         self.labels = labels
         self.xaxis = xaxis
@@ -122,7 +126,8 @@ def __init__(self, X, orientation='bottom', labels=None, colorscale=None,
         (dd_traces, xvals, yvals,
             ordered_labels, leaves) = self.get_dendrogram_traces(X, colorscale,
                                                                  distfun,
-                                                                 linkagefun)
+                                                                 linkagefun, 
+                                                                 hovertext)
 
         self.labels = ordered_labels
         self.leaves = leaves
@@ -231,7 +236,7 @@ def set_figure_layout(self, width, height):
 
         return self.layout
 
-    def get_dendrogram_traces(self, X, colorscale, distfun, linkagefun):
+    def get_dendrogram_traces(self, X, colorscale, distfun, linkagefun, hovertext):
         """
         Calculates all the elements needed for plotting a dendrogram.
 
@@ -241,6 +246,7 @@ def get_dendrogram_traces(self, X, colorscale, distfun, linkagefun):
                                    from the observations
         :param (function) linkagefun: Function to compute the linkage matrix
                                       from the pairwise distances
+        :param (list) hovertext: List of hovertext for constituent traces of dendrogram
         :rtype (tuple): Contains all the traces in the following order:
             (a) trace_list: List of Plotly trace objects for dendrogram tree
             (b) icoord: All X points of the dendrogram tree as array of arrays
@@ -278,11 +284,16 @@ def get_dendrogram_traces(self, X, colorscale, distfun, linkagefun):
             else:
                 ys = icoord[i]
             color_key = color_list[i]
+            hovertext_label = None
+            if hovertext:
+                hovertext_label = hovertext[i]
             trace = graph_objs.Scatter(
                 x=np.multiply(self.sign[self.xaxis], xs),
                 y=np.multiply(self.sign[self.yaxis], ys),
                 mode='lines',
-                marker=graph_objs.Marker(color=colors[color_key])
+                marker=graph_objs.Marker(color=colors[color_key]),
+                text=hovertext_label,
+                hoverinfo='text'
             )
 
             try: