Remove stddev and direction columns

meta/import_velcom_data

@@ -6,14 +6,9 @@ import json
 import math
 import re
 import sqlite3
+import statistics
 import urllib.request
 
-DIRECTION = {
-    "LESS_IS_BETTER": -1,
-    "NEUTRAL": 0,
-    "MORE_IS_BETTER": 1,
-}
-
 
 def format_time(time):
     # If the fractional part of the second is not exactly 3 or 6 digits long,
@@ -31,15 +26,6 @@ def format_time(time):
     return time.isoformat()
 
 
-def stddev(values):
-    if len(values) < 2:
-        return None
-    N = len(values)
-    mean = sum(values) / N
-    variance = sum(pow(value - mean, 2) for value in values) / (N - 1)
-    return math.sqrt(variance)
-
-
 def get_run_data(con, run_id):
     (
         runner_name,
@@ -73,7 +59,6 @@ def get_run_data(con, run_id):
         benchmark,
         metric,
         unit,
-        interpretation,
         error,
     ) in con.execute(
         """
@@ -82,7 +67,6 @@ def get_run_data(con, run_id):
             benchmark,
             metric,
             unit,
-            interpretation,
             error
         FROM measurement
         WHERE run_id = ?
@@ -101,10 +85,8 @@ def get_run_data(con, run_id):
         values = [value for (value,) in values]
 
         measurements[f"{metric}/{benchmark}"] = {
-            "value": sum(values),
-            "stddev": stddev(values),
+            "value": statistics.mean(values),
             "unit": unit,
-            "direction": DIRECTION.get(interpretation),
         }
 
     if error_type: