private static double calculateSSE(double[] data, double[] smoothedData) {
        double sse = 0;
        for (int i = 0 ; i < data.length ; i++) {
            sse += Math.pow(smoothedData[i] - data[i], 2);
        }
        return sse;
    }
Performs double exponential smoothing for given time series.
This method is suitable for fitting series with linear trend.

@param data  An array containing the recorded data of the time series
@param alpha Smoothing factor for data (0 &lt; alpha &lt; 1)
@param beta  Smoothing factor for trend (0 &lt; beta &lt; 1)

@return Instance of model that can be used to forecast future values
src/main/java/eu/hansolo/tilesfx/tools/DoubleExponentialSmoothingForLinearSeries.java