const double PI         = 3.141592653589793238462643;
const double TWO_PI     = 6.283185307179586476925287;
const double THREE_PI   = 9.424777960769379715387930;
const double FOUR_PI    = 12.56637061435917295385057;
const double SQRT_2PI   = 2.506628274631000502415765;
const double R_SQRT_2PI = 3.989422804014326779399461;

const double e          = 2.718281828459045235360287;

const double SQRT_2     = 1.4142135623730950488;
const double SQRT_3     = 1.7320508075688772935;
const double SQRT_5     = 2.2360679774997896964;
const double SQRT_7     = 2.6457513110645905905;

const double RAD_TO_DEG = 57.295779513082320876798155;
const double DEG_TO_RAD = 0.017453292519943295769237;