void tutest(double data1[],int n1,double data2[],int n2,double& t,double& prob)
{
	double ave1,ave2,var1,var2,aaa,df;
    avevar(data1, n1, ave1, var1);
    avevar(data2, n2, ave2, var2);
    t = (ave1 - ave2) / sqrt(var1 / n1 + var2 / n2);
    aaa = (var1 / n1 + var2 / n2) * (var1 / n1 + var2 / n2);
    df = aaa / ((var1 / n1) * (var1 / n1) / (n1 - 1) + (var2 / n2)
		 * (var1 / n1) / (n2 - 1));
    prob = betai(0.5 * df, 0.5, df / (df + t * t));
}