public static double[] summaryStats(Vec xData, Vec yData)
    {
        double[] values = new double[1];
        
        //Sx, sum of x values
        values[0] = xData.sum();
        
        //Sy, sum of y values
        values[1] = yData.sum();
        
        double tmp = 0;
        
        
        
        //Sxx
        for(int i = 0; i < xData.length(); i++)
            tmp += Math.pow(xData.get(i), 2);
        values[2] = tmp;
        //Syy
        tmp = 0;
        for(int i = 0; i < xData.length(); i++)
            tmp += Math.pow(yData.get(i), 2);
        values[3] = tmp;
        
        //Sxy
        tmp = 0;
        for(int i = 0; i < xData.length(); i++)
            tmp += xData.get(i)*yData.get(i);
        values[4] = tmp;
        
        return values;
    }
public static double [ ] summaryStats ( Vec xData , Vec yData ) { double [ ] values = new double [ 1 ] ; values [ 0 ] = xData . sum ( ) ; values [ 1 ] = yData . sum ( ) ; double tmp = 0 ; for ( int i = 0 ; i < xData . length ( ) ; i ++ ) tmp += Math . pow ( xData . get ( i ) , 2 ) ; values [ 2 ] = tmp ; tmp = 0 ; for ( int i = 0 ; i < xData . length ( ) ; i ++ ) tmp += Math . pow ( yData . get ( i ) , 2 ) ; values [ 3 ] = tmp ; tmp = 0 ; for ( int i = 0 ; i < xData . length ( ) ; i ++ ) tmp += xData . get ( i ) * yData . get ( i ) ; values [ 4 ] = tmp ; return values ; }
Computes several summary statistics from the two data sets. These are: <br>

Index 0: S<sub>x</sub>  <br>
Index 1: S<sub>y</sub>  <br>
Index 2: S<sub>xx</sub> <br>
Index 3: S<sub>yy</sub> <br>
Index 4: S<sub>xy</sub>

@param xData the x values of the data set
@param yData the y values of the data set
@return several summary statistics of the 2 variables