2 files changed, 39 insertions, 0 deletions

diff --git a/csit.infra.dash/app/cdash/utils/constants.py b/csit.infra.dash/app/cdash/utils/constants.py
index 12d7ee5702..1aedb9b96f 100644
--- a/csit.infra.dash/app/cdash/utils/constants.py
+++ b/csit.infra.dash/app/cdash/utils/constants.py
@@ -142,6 +142,7 @@ class Constants:
 
     NORM_FREQUENCY = 2.0  # [GHz]
     FREQUENCY = {  # [GHz]
+        "1n-aws": 1.000,
         "2n-aws": 1.000,
         "2n-dnv": 2.000,
         "2n-clx": 2.300,
@@ -291,6 +292,18 @@ class Constants:
     REPORT_DOWNLOAD_FILE_NAME = "iterative_data.csv"
 
     ############################################################################
+    # Comparisons.
+
+    # The title.
+    COMP_TITLE = "Per Release Performance Comparisons"
+
+    # The pathname prefix for the application.
+    COMP_ROUTES_PATHNAME_PREFIX = "/comparisons/"
+
+    # Default name of downloaded file with selected data.
+    COMP_DOWNLOAD_FILE_NAME = "comparison_data.csv"
+
+    ############################################################################
     # Statistics.
 
     # The title.
diff --git a/csit.infra.dash/app/cdash/utils/utils.py b/csit.infra.dash/app/cdash/utils/utils.py
index 424456088d..68099987d2 100644
--- a/csit.infra.dash/app/cdash/utils/utils.py
+++ b/csit.infra.dash/app/cdash/utils/utils.py
@@ -17,6 +17,7 @@
 import pandas as pd
 import dash_bootstrap_components as dbc
 
+from math import sqrt
 from numpy import isnan
 from dash import dcc
 from datetime import datetime
@@ -391,3 +392,28 @@ def get_list_group_items(
         )
 
     return children
+
+def relative_change_stdev(mean1, mean2, std1, std2):
+    """Compute relative standard deviation of change of two values.
+
+    The "1" values are the base for comparison.
+    Results are returned as percentage (and percentual points for stdev).
+    Linearized theory is used, so results are wrong for relatively large stdev.
+
+    :param mean1: Mean of the first number.
+    :param mean2: Mean of the second number.
+    :param std1: Standard deviation estimate of the first number.
+    :param std2: Standard deviation estimate of the second number.
+    :type mean1: float
+    :type mean2: float
+    :type std1: float
+    :type std2: float
+    :returns: Relative change and its stdev.
+    :rtype: float
+    """
+    mean1, mean2 = float(mean1), float(mean2)
+    quotient = mean2 / mean1
+    first = std1 / mean1
+    second = std2 / mean2
+    std = quotient * sqrt(first * first + second * second)
+    return (quotient - 1) * 100, std * 100