curvfitt.pas

第三方控件：PaintGrid.pas 网格型仪表控件源文件 Mymeter.pas 圆型仪表控件源文件 Project1是这两个控件的使用范例。 该

    tmpMinXValue:=XValues.MinValue;
    IMinYValue:=AList.MinValue;
    if FFirstCalcPoint=-1 then tmpStart:=0
                          else tmpStart:=Math.Max(0,FFirstCalcPoint);
    if FLastCalcPoint=-1 then tmpEnd:=Count-1
                         else tmpEnd:=Math.Min(Count-1,FLastCalcPoint);

    tmpCount:=(tmpEnd-tmpStart+1);
    if tmpCount>0 then
    begin
      SetLength(IXVector,tmpCount+1);
      SetLength(IYVector,tmpCount+1);
      try
        for t:=1 to tmpCount do
        begin
          tmpPos:=t+tmpStart-1;
          IXVector[t]:=XValues.Value[tmpPos]-tmpMinXValue;
          IYVector[t]:=AList.Value[tmpPos]-IMinYValue;
        end;

        PolyFitting(tmpCount,FPolyDegree,IXVector,IYVector,IAnswerVector);
        AddFittedPoints(Source);
      finally
        IYVector:=nil;
        IXVector:=nil;
      end;
    end;
  end;
end;

{ calculates and returns the Y value corresponding to a X value }
Function TCustomFittingFunction.GetCurveYValue(Source:TChartSeries; Const X:Double):Double;
Begin
  result:=CalcFitting(FPolyDegree,IAnswerVector,X-Source.XValues.MinValue)+IMinYValue;
end;

{ TCustomTrendFunction }
constructor TCustomTrendFunction.Create(AOwner: TComponent);
begin
  inherited;
  IStyle:=tsNormal;
end;

Function TCustomTrendFunction.Calculate(SourceSeries:TChartSeries; First,Last:Integer):Double;
begin
  result:=0;
end;

Function TCustomTrendFunction.CalculateMany(SourceSeriesList:TList; ValueIndex:Integer):Double;
begin
  result:=0;
end;

Procedure TCustomTrendFunction.CalculateAllPoints( Source:TChartSeries;
                                             NotMandatorySource:TChartValueList);
begin
  CalculatePeriod(Source,0,0,Source.Count-1);
end;

Procedure TCustomTrendFunction.CalculatePeriod( Source:TChartSeries;
                                          Const tmpX:Double;
                                          FirstIndex,LastIndex:Integer);
Var m : Double;
    b : Double;

  Procedure AddPoint(Const Value:Double);
  var tmp : Double;
  begin
    Case IStyle of
      tsNormal     : tmp:=m*Value+b;
      tsLogarithmic: tmp:=m*Ln(Value*b);
    else
       tmp:=m*Exp(b*Value);
    end;

    if Source.YMandatory then ParentSeries.AddXY(Value, tmp)
                         else ParentSeries.AddXY(tmp, Value)
  end;

begin
  if CalculateTrend(m,b,Source,FirstIndex,LastIndex) then
  With Source.NotMandatoryValueList do
  begin
    if Order=loNone then
    begin
      AddPoint(MinValue);
      AddPoint(MaxValue);
    end
    else
    begin
      AddPoint(Value[FirstIndex]);
      AddPoint(Value[LastIndex]);
    end;
  end;
end;

Function TCustomTrendFunction.CalculateValues(Source:TChartSeries; FirstIndex,LastIndex:Integer):Boolean;
var tmpAll : Boolean;
    t      : Integer;
    x      : TChartValue;
    y      : TChartValue;
begin
  if FirstIndex=TeeAllValues then
  begin
    FirstIndex:=0;
    LastIndex:=Source.Count-1;
  end;

  ICount:=LastIndex-FirstIndex+1;

  result:=ICount>1;

  if result then
  With Source do
  begin
    tmpAll:=(IStyle=tsNormal) and (ICount=Count);

    if tmpAll then
    begin
      SumX:=NotMandatoryValueList.Total;
      SumY:=ValueList(Source).Total;
    end
    else
    begin
      SumX:=0;
      SumY:=0;
    end;

    SumX2:=0;
    SumY2:=0;
    SumXY:=0;

    With ValueList(Source) do
    for t:=FirstIndex to LastIndex do
    begin
      x:=NotMandatoryValueList.Value[t];
      if IStyle=tsNormal then y:=Value[t]
                         else
                         if Value[t]<>0 then y:=Ln(Value[t])
                                        else y:=0;

      SumXY:=SumXY+x*y;
      SumX2:=SumX2+Sqr(x);
      SumY2:=SumY2+Sqr(y);

      if not tmpAll then
      begin
        SumX:=SumX+x;
        SumY:=SumY+y;
      end;
    end;
  end;
end;

Function TCustomTrendFunction.Coefficient(Source:TChartSeries; FirstIndex,LastIndex:Integer):Double;
var tmpNumerator   : Double;
    tmpDenominator : Double;
begin
  if CalculateValues(Source,FirstIndex,LastIndex) then
  begin
    tmpNumerator:=SumXY - SumX*SumY/ICount;
    tmpDenominator:=Sqrt( (SumX2 - SumX*SumX/ICount) * (SumY2 - SumY*SumY/ICount) );
    if tmpDenominator=0 then
       result:=1
    else
       result:=tmpNumerator/tmpDenominator;
  end
  else result:=1;
end;

Function TCustomTrendFunction.CalculateTrend(Var m,b:Double; Source:TChartSeries; FirstIndex,LastIndex:Integer):Boolean;
var Divisor : Double;
begin
  result:=CalculateValues(Source,FirstIndex,LastIndex);

  if result then
    if IStyle=tsNormal then
    begin
      Divisor:=ICount*SumX2-Sqr(SumX);

      if Divisor<>0 then
      begin
        m:=( (ICount*SumXY) - (SumX*SumY) ) / Divisor;
        b:=( (SumY*SumX2) - (SumX*SumXY) ) / Divisor;
      end
      else
      begin
        m:=1;
        b:=0;
      end;
    end
    else
    begin
      SumX:=SumX/ICount;
      SumY:=SumY/ICount;

      Divisor:= (SumX2-(ICount*SumX*SumX));

      if Divisor=0 then b:=1
                   else b:=(SumXY-(ICount*SumX*SumY))/Divisor;

      if IStyle=tsLogarithmic then m:=SumY-b*SumX
                              else m:=Exp(SumY-b*SumX);
    end;
end;

{ TExpTrendFunction }
constructor TExpTrendFunction.Create(AOwner: TComponent);
begin
  inherited;
  IStyle:=tsExponential;
end;

{ TCorrelationFunction }

function TCorrelationFunction.Calculate(SourceSeries: TChartSeries; First,
  Last: Integer): Double;
begin
  result:=Coefficient(SourceSeries,First,Last);
end;

function TCorrelationFunction.CalculateMany(SourceSeriesList: TList;
  ValueIndex: Integer): Double;
begin
  result:=0;
end;

procedure TCorrelationFunction.CalculatePeriod(Source: TChartSeries;
  const tmpX: Double; FirstIndex, LastIndex: Integer);

  procedure AddPoint(const x,y:Double);
  begin
    with ParentSeries do
    if YMandatory then ParentSeries.AddXY(x,y)
                  else ParentSeries.AddXY(y,x);
  end;

var tmp : Double;
begin
  tmp:=Calculate(Source,FirstIndex,LastIndex);
  if ParentSeries.AllowSinglePoint then
     ParentSeries.Add(tmp)
  else
  begin
    AddPoint(Source.NotMandatoryValueList.MinValue,tmp);
    AddPoint(Source.NotMandatoryValueList.MaxValue,tmp);
  end;
end;

initialization
  RegisterTeeFunction( TCurveFittingFunction, {$IFNDEF CLR}@{$ENDIF}TeeMsg_FunctionCurveFitting,
                                              {$IFNDEF CLR}@{$ENDIF}TeeMsg_GalleryExtended );
  RegisterTeeFunction( TTrendFunction, {$IFNDEF CLR}@{$ENDIF}TeeMsg_FunctionTrend,
                                       {$IFNDEF CLR}@{$ENDIF}TeeMsg_GalleryExtended );
  RegisterTeeFunction( TExpTrendFunction, {$IFNDEF CLR}@{$ENDIF}TeeMsg_FunctionExpTrend,
                                          {$IFNDEF CLR}@{$ENDIF}TeeMsg_GalleryExtended );
  RegisterTeeFunction( TCorrelationFunction, {$IFNDEF CLR}@{$ENDIF}TeeMsg_FunctionCorrelation,
                                             {$IFNDEF CLR}@{$ENDIF}TeeMsg_GalleryExtended );
finalization
  UnRegisterTeeFunctions([ TCurveFittingFunction, TTrendFunction,
                           TExpTrendFunction, TCorrelationFunction ]);
end.