| #!/usr/bin/env python |
| |
| """ |
| Licensed to the Apache Software Foundation (ASF) under one |
| or more contributor license agreements. See the NOTICE file |
| distributed with this work for additional information |
| regarding copyright ownership. The ASF licenses this file |
| to you under the Apache License, Version 2.0 (the |
| "License"); you may not use this file except in compliance |
| with the License. You may obtain a copy of the License at |
| |
| http://www.apache.org/licenses/LICENSE-2.0 |
| |
| Unless required by applicable law or agreed to in writing, software |
| distributed under the License is distributed on an "AS IS" BASIS, |
| WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| See the License for the specific language governing permissions and |
| limitations under the License. |
| """ |
| |
| from math import sqrt |
| |
| def sample_standard_deviation(lst): |
| """calculates standard deviation""" |
| if len(lst) < 2: |
| return 0 |
| variance = sum([(element-mean(lst))**2 for element in lst]) / (len(lst) - 1) |
| return sqrt(variance) |
| |
| def mean(lst): |
| """calculates mean""" |
| if len(lst) < 1: |
| return 0 |
| return sum(lst) / len(lst) |
| |
| def sample_standard_deviation_percentage(lst): |
| """calculates sample standard deviation percentage""" |
| try: |
| return sample_standard_deviation(lst) / mean(lst) * 100 |
| except ZeroDivisionError: |
| # should not be a case for this alert |
| return 0 |
| |
| def count(lst): |
| """calculates number of data points""" |
| return len(lst) |
