Book Image

Python Data Analysis - Third Edition

By : Avinash Navlani, Ivan Idris
5 (1)
Book Image

Python Data Analysis - Third Edition

5 (1)
By: Avinash Navlani, Ivan Idris

Overview of this book

Data analysis enables you to generate value from small and big data by discovering new patterns and trends, and Python is one of the most popular tools for analyzing a wide variety of data. With this book, you’ll get up and running using Python for data analysis by exploring the different phases and methodologies used in data analysis and learning how to use modern libraries from the Python ecosystem to create efficient data pipelines. Starting with the essential statistical and data analysis fundamentals using Python, you’ll perform complex data analysis and modeling, data manipulation, data cleaning, and data visualization using easy-to-follow examples. You’ll then understand how to conduct time series analysis and signal processing using ARMA models. As you advance, you’ll get to grips with smart processing and data analytics using machine learning algorithms such as regression, classification, Principal Component Analysis (PCA), and clustering. In the concluding chapters, you’ll work on real-world examples to analyze textual and image data using natural language processing (NLP) and image analytics techniques, respectively. Finally, the book will demonstrate parallel computing using Dask. By the end of this data analysis book, you’ll be equipped with the skills you need to prepare data for analysis and create meaningful data visualizations for forecasting values from data.
Table of Contents (20 chapters)
Section 1: Foundation for Data Analysis
Section 2: Exploratory Data Analysis and Data Cleaning
Section 3: Deep Dive into Machine Learning
Section 4: NLP, Image Analytics, and Parallel Computing

Reducing the dimensionality of data

Reducing dimensionality, or dimensionality reduction, entails scaling down a large number of attributes or columns (features) into a smaller number of attributes. The main objective of this technique is to get the best number of features for classification, regression, and other unsupervised approaches. In machine learning, we face a problem called the curse of dimensionality. This is where there is a large number of attributes or features. This means more data, causing complex models and overfitting problems.

Dimensionality reduction helps us to deal with the curse of dimensionality. It can transform data linearly and nonlinearly. Techniques for linear transformations include PCA, linear discriminant analysis, and factor analysis. Non-linear transformations include techniques such as t-SNE, Hessian eigenmaps, spectral embedding, and isometric feature mapping. Dimensionality reduction offers the following benefits:

  • It filters redundant and less important...