private static IMatrix CalculateInvertedPseudoGaussian(IMatrix b, IVector s, IVector y)
{
var syNumber = s.Mul(y);
var syNumberSqr = syNumber.Mul(syNumber);
var yByNumber = y.Mul(b.Mul(y));
var ssMatrix = s.OuterMul(s);
var second = ssMatrix.Mul(syNumber.Sum(yByNumber)).Div(syNumberSqr);
var ysMatrix = y.OuterMul(s);
var syMatrix = s.OuterMul(y);
var third = b.Mul(ysMatrix).Sum(syMatrix.Mul(b)).Div(syNumber);
return b.Sum(second).Sub(third);
}
