Plot latency criticality

Create a plot file that visualises the latency criticality of code
regions.

xlap/analyse/latency.py

@@ -2,6 +2,7 @@ import pandas as pd
 import matplotlib.pyplot as plt
 from xlap.analyse.util import get_outlier_threshold, extract_durations, box
 from scipy.stats.stats import pearsonr
+import numpy as np
 import sys
 
 
@@ -119,10 +120,20 @@ def _plot_critical_regions(df,hdb):
     """
     plot regions, sorted by latency criticality
     """
-    # TODO: actually plot the data
     for region in sorted(hdb, key = lambda x: -x['Correlation']):
         print("%-10f %10s -> %10s"%(region['Correlation'], region['Start'], region['End']), file=sys.stderr)
 
+    relevant = sorted([x for x in hdb if x['Correlation'] > 0], key = lambda x: -x['Correlation'])
+    x = np.arange(len(relevant))
+    bars = plt.bar(x, list(map(lambda x: x['Correlation'], relevant)))
+    # TODO: find a more elegant solution for the label text
+    plt.xticks(x, list(map(lambda x: "%s-%s"%(x['Start'][:-2], x['End'][:-2]) , relevant)), rotation=90)
+    plt.tight_layout()
+    plt.savefig("latency-criticality.png")
+    plt.close()
+
+
+
 
 def analyse(df, config):
     hb = []