private double GaussianDirection(Minutia middleMinutia, Minutia minutia, double anglePoint)
{
double common = Math.Sqrt(2) * SigmaDirection;
double angle = CylinderHelper.GetAngleDiff(anglePoint,
CylinderHelper.GetAngleDiff(middleMinutia.Angle, minutia.Angle));
double first = Erf(((angle + HeightCell / 2)) / common);
double second = Erf(((angle - HeightCell / 2)) / common);
return((first - second) / 2);
}