74 lines
1.8 KiB
Python
74 lines
1.8 KiB
Python
# Copyright 2017 The Chromium OS Authors. All rights reserved.
|
|
# Use of this source code is governed by a BSD-style license that can be
|
|
# found in the LICENSE file.
|
|
|
|
from math import ceil, floor, sqrt
|
|
|
|
|
|
def get_kth_percentile(num_list, k):
|
|
"""
|
|
Computes the k-th percentile of a list of numbers.
|
|
|
|
@param num_list: list with numbers.
|
|
@param k: the percentile to be computed.
|
|
|
|
@returns the kth percentile value of the list.
|
|
|
|
"""
|
|
if not num_list:
|
|
return 0
|
|
assert k >= 0 and k <= 1
|
|
i = k * (len(num_list) - 1)
|
|
c, f = int(ceil(i)), int(floor(i))
|
|
if c == f:
|
|
return num_list[c]
|
|
return round((i - f) * num_list[c] + (c - i) * num_list[f], 2)
|
|
|
|
|
|
def get_median(num_list):
|
|
"""
|
|
Computes the median of a list of numbers.
|
|
|
|
@param num_list: a list with numbers.
|
|
|
|
@returns the median value of the numbers.
|
|
|
|
"""
|
|
if not num_list:
|
|
return 0
|
|
num_list.sort()
|
|
size = len(num_list)
|
|
if size % 2 != 0:
|
|
return num_list[size / 2]
|
|
return round((num_list[size / 2] + num_list[size / 2 - 1]) / 2.0, 2)
|
|
|
|
|
|
def get_average(num_list):
|
|
"""
|
|
Computes mean of a list of numbers.
|
|
|
|
@param num_list: a list with numbers.
|
|
|
|
@returns the average value computed from the list of numbers.
|
|
|
|
"""
|
|
if not num_list:
|
|
return 0
|
|
return round(float(sum(num_list)) / len(num_list) , 2)
|
|
|
|
|
|
def get_std_dev(num_list):
|
|
"""
|
|
Computes standard deviation of a list of numbers.
|
|
|
|
@param num_list: a list with numbers.
|
|
|
|
@returns Standard deviation computed from the list of numbers.
|
|
|
|
"""
|
|
n = len(num_list)
|
|
if not num_list or n == 1:
|
|
return 0
|
|
mean = float(sum(num_list)) / n
|
|
variance = sum([(elem - mean) ** 2 for elem in num_list]) / (n -1)
|
|
return round(sqrt(variance), 2) |