compare has a syntax error where it is missing the path to sem().

bin/compare

 #!/usr/bin/env python
 
 import argparse
 import sys
 
 have_scipy = True
 try:
     import scipy.stats
 except:
     have_scipy = False
@@ skipping 27 matching lines @@
 def mean(xs):
     return sum(xs) / len(xs)
 
 ps = []
 for key in common:
     p, asem, bsem = 0, 0, 0
     m = mean if args.use_means else min
     am, bm = m(a[key]), m(b[key])
     if have_scipy:
         _, p = scipy.stats.mannwhitneyu(a[key], b[key])
-        asem, bsem = scipy.stats.sem(a[key]), sem(b[key])
+        asem, bsem = scipy.stats.sem(a[key]), scipy.stats.sem(b[key])
     ps.append((bm/am, p, key, am, bm, asem, bsem))
 ps.sort(reverse=True)
 
 def humanize(ns):
     for threshold, suffix in [(1e9, 's'), (1e6, 'ms'), (1e3, 'us'), (1e0, 'ns')]:
         if ns > threshold:
             return "%.3g%s" % (ns/threshold, suffix)
 
 maxlen = max(map(len, common))
 
 # We print only signficant changes in benchmark timing distribution.
 bonferroni = SIGNIFICANCE_THRESHOLD / len(ps)  # Adjust for the fact we've run multiple tests.
 for ratio, p, key, am, bm, asem, bsem in ps:
     if p < bonferroni:
         str_ratio = ('%.2gx' if ratio < 1 else '%.3gx') % ratio
         if args.use_means:
             print '%*s\t%6s(%6s) -> %6s(%6s)\t%s' % (maxlen, key, humanize(am), humanize(asem),
                                                      humanize(bm), humanize(bsem), str_ratio)
         else:
             print '%*s\t%6s -> %6s\t%s' % (maxlen, key, humanize(am), humanize(bm), str_ratio)