Book Image

Python Data Analysis Cookbook

By : Ivan Idris
Book Image

Python Data Analysis Cookbook

By: Ivan Idris

Overview of this book

Data analysis is a rapidly evolving field and Python is a multi-paradigm programming language suitable for object-oriented application development and functional design patterns. As Python offers a range of tools and libraries for all purposes, it has slowly evolved as the primary language for data science, including topics on: data analysis, visualization, and machine learning. Python Data Analysis Cookbook focuses on reproducibility and creating production-ready systems. You will start with recipes that set the foundation for data analysis with libraries such as matplotlib, NumPy, and pandas. You will learn to create visualizations by choosing color maps and palettes then dive into statistical data analysis using distribution algorithms and correlations. You’ll then help you find your way around different data and numerical problems, get to grips with Spark and HDFS, and then set up migration scripts for web mining. In this book, you will dive deeper into recipes on spectral analysis, smoothing, and bootstrapping methods. Moving on, you will learn to rank stocks and check market efficiency, then work with metrics and clusters. You will achieve parallelism to improve system performance by using multiple threads and speeding up your code. By the end of the book, you will be capable of handling various data analysis techniques in Python and devising solutions for problem scenarios.
Table of Contents (23 chapters)
Python Data Analysis Cookbook
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Glossary
Index

Moving block bootstrapping time series data


If you followed along with the Block bootstrapping time series data recipe, you are now aware of a simple bootstrapping scheme for time series data. The moving block bootstrapping algorithm is a bit more complicated. In this scheme, we generate overlapping blocks by moving a fixed size window, similar to the moving average. We then assemble the blocks to create new data samples.

In this recipe, we will apply the moving block bootstrap to annual temperature data to generate lists of second difference medians and the slope of an AR(1) model. This is an autoregressive model with lag 1. Also, we will try to neutralize outliers and noise with a median filter.

How to do it...

The following code snippets are from the moving_boot.ipynb file in this book's code bundle:

  1. The imports are as follows:

    import dautil as dl
    import numpy as np
    import pandas as pd
    import matplotlib.pyplot as plt
    import seaborn as sns
    import ch6util
    from scipy.signal import medfilt
    from...