Is there a function in java to get moving average

Question

I have a situation where I need to process 5000 samples from a device in every 0.5 sec.

Lets say the window size is 100, then there would be 50 points resulting fro

Answer 1

Here's a good implementation, using BigDecimal:

import java.math.BigDecimal;
import java.math.RoundingMode;
import java.util.LinkedList;
import java.util.Queue;

public class MovingAverage {

    private final Queue window = new LinkedList();
    private final int period;
    private BigDecimal sum = BigDecimal.ZERO;

    public MovingAverage(int period) {
        assert period > 0 : "Period must be a positive integer";
        this.period = period;
    }

    public void add(BigDecimal num) {
        sum = sum.add(num);
        window.add(num);
        if (window.size() > period) {
            sum = sum.subtract(window.remove());
        }
    }

    public BigDecimal getAverage() {
        if (window.isEmpty()) return BigDecimal.ZERO; // technically the average is undefined
        BigDecimal divisor = BigDecimal.valueOf(window.size());
        return sum.divide(divisor, 2, RoundingMode.HALF_UP);
    }
}