lnst.Common.Utils: use statistics in std_deviation

This function was written back in 2015 when we couldn't use python3 yet and statistics module was added in 3.4. At the same time, the formula used is "incorrect", this calculates the POPULATION std deviation... whereas we really should be using a SAMPLE standard deviation formula. Signed-off-by: Ondrej Lichtner <[email protected]>
LNST-project · Feb 8, 2024 · 7646480 · 7646480
1 parent 2d15587
commit 7646480
Showing 1 changed file with 3 additions and 4 deletions.
diff --git a/lnst/Common/Utils.py b/lnst/Common/Utils.py
@@ -21,7 +21,7 @@
 import errno
 import ast
 import collections
-import math
+import statistics
 import itertools
 from collections.abc import Iterable, Callable
 from contextlib import AbstractContextManager
@@ -287,10 +287,9 @@ def dict_to_dot(original_dict, prefix=""):
     return return_list
 
 def std_deviation(values):
-    if len(values) <= 0:
+    if len(values) <= 1:
         return 0.0
-    avg = sum(values) / float(len(values))
-    return math.sqrt(sum([(float(i) - avg)**2 for i in values])/len(values))
+    return statistics.stdev(values)
 
 def deprecated(func):
     """