Merge pull request #3558 from ga7g08/multiple-side-by-side-histograms

tacaswell · tacaswell · commit dcc39c6b42b1 · 2014-10-18T13:08:04.000-04:00
EXP : Adds multiple histograms side-by-side example
diff --git a/examples/statistics/multiple_histograms_side_by_side.py b/examples/statistics/multiple_histograms_side_by_side.py
@@ -0,0 +1,43 @@
+
+"""
+Demo of how to produce multiple histograms side by side
+"""
+
+import numpy as np
+import matplotlib.pyplot as plt
+
+number_of_bins = 20
+
+# An example of three data sets to compare
+number_of_data_points = 1000
+labels = ["A", "B", "C"]
+data_sets = [np.random.normal(0, 1, number_of_data_points),
+            np.random.normal(6, 1, number_of_data_points),
+            np.random.normal(-3, 1, number_of_data_points)]
+
+# Computed quantities to aid plotting
+hist_range = (np.min(data_sets), np.max(data_sets))
+binned_data_sets = [np.histogram(d, range=hist_range, bins=number_of_bins)[0]
+                    for d in data_sets]
+binned_maximums = np.max(binned_data_sets, axis=1)
+x_locations = np.arange(0, sum(binned_maximums), np.max(binned_maximums))
+
+# The bin_edges are the same for all of the histograms
+bin_edges = np.linspace(hist_range[0], hist_range[1], number_of_bins+1)
+centers = .5 * (bin_edges +  np.roll(bin_edges, 1))[:-1]
+heights = np.diff(bin_edges)
+
+# Cycle through and plot each histogram
+ax = plt.subplot(111)
+for x_loc, binned_data in zip(x_locations, binned_data_sets):
+    lefts = x_loc - .5 * binned_data
+    ax.barh(centers, binned_data, height=heights, left=lefts)
+
+ax.set_xticks(x_locations)
+ax.set_xticklabels(labels)
+
+ax.set_ylabel("Data values")
+ax.set_xlabel("Data sets")
+
+plt.show()
+
