void avevar(double data[], int n, double& ave, double& var)
{
    ave = 0.0;
    var = 0.0;
	int j;
	double s;
    for (j = 1; j<=n; j++)
	{
        ave = ave + data[j];
    }
    ave = ave / n;
    for (j = 1; j<=n; j++)
	{
        s = data[j] - ave;
        var = var + s * s;
    }
    var = var / (n - 1);
}