MtxIntDiff.QuadGauss Function

Integration by using Gauss quadrature algorithm with no additional parameters for Fun.

Pascal

function QuadGauss(Fun: TRealFunction; lb: double; ub: double; out StopReason: TIntStopReason; const FloatPrecision: TMtxFloatPrecision; QMethod: TQuadMethod = qmGauss; Tolerance: double = 1.0E-4; MaxIter: Integer = 8): double; overload;

File

MtxIntDiff

Returns

the numerical approximate on integral of function Fun between limits lb and ub.

Description

This version calculates base points and weights on the fly.

Notes

Use this overload if integrating function is defined only by double parameter(s).

Example

Evaluate fuction Sin(x)*Exp(-x^2) on interval [-PI/2, PI]. Use default Gauss base points and weights.

Uses Math387, MtxIntDiff; // Integrating function function IntFunc(const Parameters: TVec; const Constants: TVec; const ObjConst: Array of TObject): double; var x: double; begin x := Parameters[0]; IntFunc:= Sin(x)*Exp(-x*x); end; // Integrate procedure DoIntegrate; var area: double; sr: TIntStopReason; begin area := QuadGauss(IntFunc,-0.5*PI,PI,sr); end;

#include "MtxExpr.hpp" #include "Math387.hpp" #include "MtxIntDiff.hpp" // Integrating function double __fastcall IntFun(TVec* const Parameters, TVec* const Constants, System::TObject* const * ObjConst, const int ObjConst_Size) { double x = (*Parameters)[0]; return Math.Sin(x)*Math.Exp(-x*x); } void __fastcall Example(); { TIntStopReason sr; double area = QuadGauss(IntFun,0.0,5*PI,sr); }

MtxIntDiff, Functions, Example

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