Book Image

Practical Data Analysis

By : Hector Cuesta
Book Image

Practical Data Analysis

By: Hector Cuesta

Overview of this book

Plenty of small businesses face big amounts of data but lack the internal skills to support quantitative analysis. Understanding how to harness the power of data analysis using the latest open source technology can lead them to providing better customer service, the visualization of customer needs, or even the ability to obtain fresh insights about the performance of previous products. Practical Data Analysis is a book ideal for home and small business users who want to slice and dice the data they have on hand with minimum hassle.Practical Data Analysis is a hands-on guide to understanding the nature of your data and turn it into insight. It will introduce you to the use of machine learning techniques, social networks analytics, and econometrics to help your clients get insights about the pool of data they have at hand. Performing data preparation and processing over several kinds of data such as text, images, graphs, documents, and time series will also be covered.Practical Data Analysis presents a detailed exploration of the current work in data analysis through self-contained projects. First you will explore the basics of data preparation and transformation through OpenRefine. Then you will get started with exploratory data analysis using the D3js visualization framework. You will also be introduced to some of the machine learning techniques such as, classification, regression, and clusterization through practical projects such as spam classification, predicting gold prices, and finding clusters in your Facebook friends' network. You will learn how to solve problems in text classification, simulation, time series forecast, social media, and MapReduce through detailed projects. Finally you will work with large amounts of Twitter data using MapReduce to perform a sentiment analysis implemented in Python and MongoDB. Practical Data Analysis contains a combination of carefully selected algorithms and data scrubbing that enables you to turn your data into insight.
Table of Contents (24 chapters)
Practical Data Analysis
Credits
Foreword
About the Author
Acknowledgments
About the Reviewers
www.PacktPub.com
Preface
Index

Degree distribution


The degree of a node is the number of connections (links) with other nodes. In the case of directed graphs, each node has two degrees: the out degree and the in degree. In the undirected graph, the relationship is mutual, so we just have a single degree for each node. In the following code snippet we get the source node and target node references from the file links.csv. Then we create a single list to merge the two lists (target and source). Finally, we get a dictionary (dic) of how many times each node appears in the list and we plot the result in a bar chart using matplotlib.

The file links.csv will look as follows:

edgedef>node1 VARCHAR,node2 VARCHAR
23917067,35702006
23917067,629395837
23917067,747343482
23917067,755605075
23917067,1186286815
.  .  .

The complete code snippet looks as follows:

import numpy as np
import matplotlib.pyplot as plt

links = np.genfromtxt("links.csv",
                       dtype=str,
                       delimiter=',',
           ...