Java: Data Science Made Easy

Using Apache Commons to find mean

In our final mean examples, we use Apache Commons libraries, also introduced in Chapter 3, Data Cleaning. We first create a Mean object and then execute the evaluate method using our testData. This method returns a double, representing the mean of the values in the array:

Mean mean = new Mean(); double average = mean.evaluate(testData); out.println("The mean is " + average); 

Our output is the following:

The mean is 16.19

Apache Commons also provides a helpful DescriptiveStatistics class. We will use this later to demonstrate median and standard deviation, but first we will begin by calculating the mean. Using the SynchronizedDescriptiveStatistics class is advantageous as it is synchronized and therefore ...