Book Image

Python Data Analysis - Second Edition

By : Ivan Idris
Book Image

Python Data Analysis - Second Edition

By: Ivan Idris

Overview of this book

Data analysis techniques generate useful insights from small and large volumes of data. Python, with its strong set of libraries, has become a popular platform to conduct various data analysis and predictive modeling tasks. With this book, you will learn how to process and manipulate data with Python for complex analysis and modeling. We learn data manipulations such as aggregating, concatenating, appending, cleaning, and handling missing values, with NumPy and Pandas. The book covers how to store and retrieve data from various data sources such as SQL and NoSQL, CSV fies, and HDF5. We learn how to visualize data using visualization libraries, along with advanced topics such as signal processing, time series, textual data analysis, machine learning, and social media analysis. The book covers a plethora of Python modules, such as matplotlib, statsmodels, scikit-learn, and NLTK. It also covers using Python with external environments such as R, Fortran, C/C++, and Boost libraries.
Table of Contents (22 chapters)
Python Data Analysis - Second Edition
Credits
About the Author
About the Reviewers
www.PacktPub.com
Customer Feedback
Preface
Key Concepts
Online Resources

Support vector regression


As mentioned before, support vector machines can be used for regression. In the case of regression, we are using a hyperplane not to separate points, but for a fit. A learning curve is a way of visualizing the behavior of a learning algorithm. It is a plot of training and test scores for a range of train data sizes. Creating a learning curve forces us to train the estimator multiple times and is, therefore, on aggregate, slow. We can compensate for this by creating multiple concurrent estimator jobs. Support vector regression is one of the algorithms that may require scaling. If we do this, then we get the following top scores:

Max test score Rain 0.0161004084576
Max test score Boston 0.662188537037

This is similar to the results obtained with the ElasticNetCV class. Many scikit-learn classes have an n_jobs parameter for that purpose. As a rule of thumb, we often create as many jobs as there are CPUs in our system. The jobs are created using the standard...