曲线拟合源代码

OptionExplicitDimX()AsSingle,Y()AsSingleDimA(20,20)AsSingle,MAsInteger,B()AsSingle'最多取20次的拟合DimNAsInteger,IAsInteger,JAsIntegerDimxiaoA()AsSingleDimXminAsSingle,XmaxAsSingleDimYminAsSingle,YmaxAsSingleDimXoAsSingle,YoAsSinglePrivateSubZuoDian(X()AsSingle,Y()AsSingle)DimXLAsSingleDimYLAsSingleN=UBound(X):Picture1.Cls '确定数组的指定维的最大可用下标Xmin=X(1):Xmax=X(1):Xo=X(1):Yo=Y(1)Ymin=Y(1):Ymax=Y(1)ForI=1ToNIfXmin>X(I)Then '(实现比较问题)Xmin=X(I)Xo=Xmin:Yo=Y(I) '后面画曲线时用到EndIfIfXmax<X(I)ThenXmax=X(I)IfYmin>Y(I)ThenYmin=Y(I)IfYmax<Y(I)ThenYmax=Y(I)NextIXL=Xmax-Xmin:YL=Ymax-YminPicture1.Scale(Xmin-XL/10,Ymax+YL/10)-(Xmax+XL/10,Ymin-YL/10)Picture1.DrawWidth=5ForI=1ToNPicture1.PSet(X(I),Y(I)),vbRed'(将对象上的点设为指定颜色)NextIPicture1.DrawWidth=1Picture1.Line(Xmin,Ymin)-(Xmax,Ymax),vbBlue,BPicture1.RefreshEndSubPrivateSubHuaQuXian(xiaoA()AsSingle)CallZuoDian(X,Y)DimYsumAsSingle,IiAsSingleForIi=XminToXmaxStep(Xmax-Xmin)/100Ysum=0ForJ=1ToMYsum=Ysum+xiaoA(J)*IiA(J-1)NextJPicturel.Line(Xo,Yo)-(Ii,Ysum)Xo=Ii:Yo=YsumNextIiEndSubPrivateSubCommand1_Click()DimFileNameAsStringDimXstrAsString,YstrAsStringOnErrorGoToerrhandleCommonDialog1.InitDir=App.Path设置初始路径 数据导入CommonDialog1.FileName=""清除文件名CommonDialog1.ShowOpen显示“打开”对话框FileName=CommonDialog1.FileName保存文件名IfLen(CommonDialog1.FileName)>0Then'File=FreeFile()'获得可用文件号OpenFileNameForInputAs#1打开文件EndIfI=0MousePointer=11DoWhileEOF(1)=FalseI=I+1ReDimPreserveX(I)ReDimPreserveY(I)MSFlexGrid1.Rows=I+1Input#1,Xstr,Ystr'分别输入各数据MSFlexGrid1.TextMatrix(I,1)=XstrX(I)=Val(Xstr)MSFlexGrid1.TextMatrix(I,2)=YstrY(I)=Val(Ystr)MSFlexGrid1.TextMatrix(I,0)=ILoopClose#1:N=I '检验一下N是否对？？？CallZuoDian(X,Y)errhandle:MousePointer=0ExitSubMousePointer=0EndSubPrivateSubCommand2_Click()'曲线拟合DimXhAsIntegerM=Val(Combo1.Text)+1EraseB:ErasexiaoA:EraseA '必不可少***********重新初始化大小固定的数组的元素，以及释放动态数组的存储空间ReDimB(M):ReDimxiaoA(1ToM)'形成方程组的各元素A(1,1)=NForI=1ToNB(1)=B(1)+Y(I)NextIForJ=2ToMForI=1ToNA(1,J)=A(1,J)+X(I)人(J-1)NextINextJForI=2ToMForJ=1ToMForXh=1ToNA(I,J)=A(I,J)+X(Xh)A(I+J-2)IfJ=1ThenB(I)=B(I)+X(Xh)a(I-1)*Y(Xh)EndIfNextXhNextJNextICallJieFangCheng(A,B,xiaoA)ForI=1ToMText1.Text=Text1.Text&"a"&I-1&"="&xiaoA(I)&";"NextIDimStrAsString:Str="y="ForI=1ToM '写方程IfI<MThenStr=Str&xiaoA(I)&"xA"&I-1&"+"ElseStr=Str&xiaoA(I)&"xA"&I-1EndIfNextITextl.Text=Textl.Text&vbCrLf&曲线方程:"&vbCrLf&StrCallHuaQuXian(xiaoA)EndSubPrivateSubCommand3_Click()DimXzhiAsSingle,YzhiAsSingleXzhi=Val(Text2.Text)Yzhi=0ForJ=1ToMYzhi=Yzhi+xiaoA(J)*XzhiA(J-1)NextJText3.Text=YzhiEndSubPrivateSubForm_Load()ForI=0To2MSFlexGridl.ColAlignment(I)=4NextIForI=1To20MSFlexGrid1.TextMatrix(I,0)=INextIEndSubPrivateSubJieFangCheng(A()AsSingle,B()AsSingle,X()AsSingle)N=UBound(B)DimTempAAsSingle,LAsInteger,KAsInteger,KkAsIntegerDimIiAsInteger,ChuShuAsSingle,SumAsSingleForI=1ToNL=0:Kk=0ForJ=IToNIfA(J,I)=0ThenL=L+1NextJForJ=IToN-LIfA(J,I)=0ThenKk=Kk+1ForK=IToNTempA=A(J,K)A(J,K)=A(N-Kk+1,K)A(N-Kk+1,K)=TempANextKTempA=B(J):B(J)=B(N-Kk+1):B(N-Kk+1)=TempAEndIfNextJForIi=IToN-LChuShu=A(Ii,I)ForJ=IToNA(Ii,J)=A(Ii,J)/ChuShuNextJB(Ii)=B(Ii)/ChuShuNextIiForIi=I+1ToN-LForJ=IToNA(Ii,J)=A(Ii,J)-A(I,J)NextJB(Ii)=B(Ii)-B(I)NextIiNextIFor