数学常量

特殊常量包含价值为数学表达式保留，这些常量可以在程序中的任意位置使用，使用 mathematical functions 取代计算值。

常量	描述	值
M_E	e	2.71828182845904523536
M_LOG2E	log2(e)	1.44269504088896340736
M_LOG10E	log10(e)	0.434294481903251827651
M_LN2	ln(2)	0.693147180559945309417
M_LN10	ln(10)	2.30258509299404568402
M_PI	pi	3.14159265358979323846
M_PI_2	pi/2	1.57079632679489661923
M_PI_4	pi/4	0.785398163397448309616
M_1_PI	1/pi	0.318309886183790671538
M_2_PI	2/pi	0.636619772367581343076
M_2_SQRTPI	2/sqrt(pi)	1.12837916709551257390
M_SQRT2	sqrt(2)	1.41421356237309504880
M_SQRT1_2	1/sqrt(2)	0.707106781186547524401

示例：

//+------------------------------------------------------------------+

//| 脚本程序启动函数                                                   |

//+------------------------------------------------------------------+

void OnStart()

  {

//--- 打印常量值

   Print("M_E = ",DoubleToString(M_E,16));

   Print("M_LOG2E = ",DoubleToString(M_LOG2E,16));

   Print("M_LOG10E = ",DoubleToString(M_LOG10E,16));

   Print("M_LN2 = ",DoubleToString(M_LN2,16));

   Print("M_LN10 = ",DoubleToString(M_LN10,16));

   Print("M_PI = ",DoubleToString(M_PI,16));

   Print("M_PI_2 = ",DoubleToString(M_PI_2,16));

   Print("M_PI_4 = ",DoubleToString(M_PI_4,16));

   Print("M_1_PI = ",DoubleToString(M_1_PI,16));

   Print("M_2_PI = ",DoubleToString(M_2_PI,16));

   Print("M_2_SQRTPI = ",DoubleToString(M_2_SQRTPI,16));

   Print("M_SQRT2 = ",DoubleToString(M_SQRT2,16));

   Print("M_SQRT1_2 = ",DoubleToString(M_SQRT1_2,16));

  }