Add Steady State Detection module

Added a Steady State Detection module containing a steady_state(data_series)
function that is able to return a boolean indicating wether or not steady
state is reached with the data_series being passed.
This module requires a data_treatment(data_series) and an average(data_series)
modules that have been added in this commit as well. The data treatment function
aims at formatting the data series that is passed to the high level steady_state
function to reach the requirement of each sub-module (slope, average and range).

Modified the Slope and Range functions so they return None when passed an empty
data series instead of 0 which was wrong. Modified the corresponding test cases.

Modified the math_range_test.py file to fix a bug in the 2 last tests.

Change-Id: I9c3854cb0a21cc37b0787b8afca0821eefaa203d
JIRA: STORPERF-60
JIRA: STORPERF-59
JIRA: STORPERF-61
JIRA: STORPERF-62
Signed-off-by: Tim Rault <tim.rault@cengn.ca>

1 files changed, 39 insertions, 0 deletions

diff --git a/storperf/utilities/data_treatment.py b/storperf/utilities/data_treatment.py
new file mode 100644
index 0000000..2368fd9
--- /dev/null
+++ b/storperf/utilities/data_treatment.py
@@ -0,0 +1,39 @@
+##############################################################################
+# Copyright (c) 2016 CENGN and others.
+#
+# All rights reserved. This program and the accompanying materials
+# are made available under the terms of the Apache License, Version 2.0
+# which accompanies this distribution, and is available at
+# http://www.apache.org/licenses/LICENSE-2.0
+##############################################################################
+
+
+def data_treatment(data_series):
+    """
+    This function aims at performing any necessary pre treatment on the
+    data_series passed to the steady_state function before being passed
+    under to the different math utilities (slope, range and average)
+    so the data can match the requirements of each algorithm.
+    The function returns a dictionary composed of three values that can be
+    accessed with the following keys : 'slope_data', 'range_data' and
+    'average_data'.
+    The data_series is currently assumed to follow the pattern :
+    [[x1,y1], [x2,y2], ..., [xm,ym]]. If this pattern were to change, or
+    the input data pattern of one of the math module, this data_treatment
+    function should be the only part of the Steady State detection module
+    that would need to be modified too.
+    """
+
+    x_values = []
+    y_values = []
+    for l in data_series:
+        x_values.append(l[0])
+        y_values.append(l[1])
+
+    treated_data = {
+        'slope_data': data_series,  # No treatment necessary so far
+        'range_data': y_values,  # The y_values only
+        'average_data': y_values
+    }
+
+    return treated_data