Book Image

Java Data Science Cookbook

By : Rushdi Shams
Book Image

Java Data Science Cookbook

By: Rushdi Shams

Overview of this book

If you are looking to build data science models that are good for production, Java has come to the rescue. With the aid of strong libraries such as MLlib, Weka, DL4j, and more, you can efficiently perform all the data science tasks you need to. This unique book provides modern recipes to solve your common and not-so-common data science-related problems. We start with recipes to help you obtain, clean, index, and search data. Then you will learn a variety of techniques to analyze, learn from, and retrieve information from data. You will also understand how to handle big data, learn deeply from data, and visualize data. Finally, you will work through unique recipes that solve your problems while taking data science to production, writing distributed data science applications, and much more - things that will come in handy at work.
Table of Contents (16 chapters)
Java Data Science Cookbook
Credits
About the Author
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface

Generating summary statistics


We can generate summary statistics for data by using the SummaryStatistics class. This is similar to the DescriptiveStatistics class used in the preceding recipe; the major difference is that unlike the DescriptiveStatistics class, the SummaryStatistics class does not store data in memory.

How to do it...

  1. Like the preceding recipe, create a method that takes a double array as argument:

            public void getSummaryStats(double[] values){ 
    
  2. Create an object of class SummaryStatistics:

            SummaryStatistics stats = new SummaryStatistics(); 
    
  3. Add all the values to this object of the SummaryStatistics class:

            for( int i = 0; i < values.length; i++) { 
                stats.addValue(values[i]); 
            } 
    
  4. Finally, use methods in the SummaryStatistics class to generate the summary statistics for the values. Close the method when you are done using the statistics:

        double mean = stats.getMean(); 
        double std = stats...