mql5/Experts/Examples/Math 3D/Functions.mqh

<EFBFBD><EFBFBD>//+------------------------------------------------------------------+

//|                                                    Functions.mqh |

//|                             Copyright 2000-2025, MetaQuotes Ltd. |

//|                                             https://www.mql5.com |

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

//--- custom function y=f(x,y)

typedef double(*MathFunction)(double, double);

//--- Math functions list

enum EnFunctionType

  {

   Chomolungma=1,

   ClimberDream=2,

   Granite=3,

   Hedgehog=4,

   Hill=5,

   Josephine=6,

   Screw=7,

   DoubleScrew=8,

   MultyExtremalScrew=9,

   Sink=10,

   Skin=11,

   Trapfall=12,

  };

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

//|  Returns a pointer to a function by its type from FunctionType   |

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

MathFunction GetMathFunction(EnFunctionType type)

  {

   MathFunction function=ClimberDreamFunction;

   switch(type)

     {

      case  Chomolungma:

         function=ChomolungmaFunction;

         break;

      case  ClimberDream:

         function=ClimberDreamFunction;

         break;

      case  Granite:

         function=GraniteFunction;

         break;

      case  Hedgehog:

         function=HedgehogFunction;

         break;

      case  Hill:

         function=HillFunction;

         break;

      case  Josephine:

         function=JosephineFunction;

         break;

      case  Screw:

         function=ScrewFunction;

         break;

      case  DoubleScrew:

         function=DoubleScrewFunction;

         break;

      case  MultyExtremalScrew:

         function=MultyExtremalScrewFunction;

         break;

      case  Sink:

         function=SinkFunction;

         break;

      case  Skin:

         function=SkinFunction;

         break;

      case  Trapfall:

         function=TrapfallFunction;

         break;

     }

   return(function);

  }

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

//| Function Chomolungma                                             |

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

double ChomolungmaFunction(double x, double y)

  {

   double a= MathCos(x*x)+MathCos(y*y);

   double b= MathPow(MathCos(5*x*y), 5);

   double c=1.0/MathPow(2, b);

//--- calculate result

   double res=a-c;

   return(res);

//---

  }

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

//| Function ClimberDream                                            |

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

double ClimberDreamFunction(double x, double y)

  {

   double a= MathSin(MathSqrt(MathAbs(x - 1.3) + MathAbs(y)));

   double b= MathCos(MathSqrt(MathAbs(MathSin(x))) + MathSqrt(MathAbs(MathSin(y))));

   double f=a+b;

//--- calculate result

   double res=MathPow(f, 4);

   return(res);

//---

  }

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

//| Function Granite                                                 |

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

double GraniteFunction(double x, double y)

  {

   double a= MathPow(MathSin(MathSqrt(MathAbs(x)+MathAbs(y))), 2);

   double b= MathPow(MathCos(MathSqrt(MathAbs(x)+MathAbs(y))), 2);

//--- calculate result

   double res=a*b;

   return(res);

//---

  }

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

//| Function Hedgehog                                                |

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

double HedgehogFunction(double x, double y)

  {

   double a1=MathSin(MathSqrt(MathAbs(x-2)+MathAbs(y)));

   double a2=MathCos(MathSqrt(MathAbs(MathSin(x)))+MathSqrt(MathAbs(MathSin(y))));

//--- calculate result

   double res=a1+a2;