static bool isSameDirection(double dir1, double dir2, double tol);
static double eval(const QString & expr, double def = 0.0);
static bool cmpDouble(double v1, double v2, double tol = 0.001);
static bool isSameDirection(double dir1, double dir2, double tol);
static double eval(const QString & expr, double def = 0.0);
static bool cmpDouble(double v1, double v2, double tol = 0.001);