implementation
//PROGRAM D1R8
//Driver for routine SVBKSB,SVDCMP
uses
  unit2;
  {$R *.DFM}
procedure TForm1.Button1Click(Sender: TObject);
var
    A,U,V:matrx2;
    X,B,W:Array[0..5] of real;
    I,J,K:Integer;  WMAX,WMIN:real;
    F:TextFile;
const
    s1='%10.1f'; s2='%13.4f';  N = 5;  N2 = 10;
begin
  SetLength(A,6,6);
  SetLength(U,6,6);
  SetLength(V,6,6);
  //輸入已知的方程組的系數矩陣
  A[1, 1]:=1.4;A[1, 2]:=2.1;A[1, 3]:=2.1;A[1, 4]:=7.4;A[1, 5]:=9.6;
  A[2, 1]:=1.6;A[2, 2]:=1.5;A[2, 3]:=1.1;A[2, 4]:=0.7;A[2, 5]:=5;
  A[3, 1]:=3.8;A[3, 2]:=8  ;A[3, 3]:=9.6;A[3, 4]:=5.4;A[3, 5]:=8.8;
  A[4, 1]:=4.6;A[4, 2]:=8.2;A[4, 3]:=8.4;A[4, 4]:=0.4;A[4, 5]:=8;
  A[5, 1]:=2.6;A[5, 2]:=2.9;A[5, 3]:=0.1;A[5, 4]:=9.9;A[5, 5]:=7.7;
  //輸入已知的方程組的右端向量B
  B[1]:=1.1;         B[2]:=1.6;
  B[3]:=4.7;         B[4]:=9.1;
  B[5]:=0.1;
  //輸出計算結果到文件
  AssignFile(F, 'd:\delphi_shu\p1\d1r8.dat');
  Rewrite(F);
  Writeln(F, '已知的方程組的右端向量B');
  For I:= 1 To N do
    Writeln(F,Format(s1,[B[I]]));
  For I:=1 To N do
    For J:=1 To N do
      U[I,J]:=A[I,J];
  SVDCMP(U,N,N,W,V);
  WMAX:=0;
  For K:=1 To N do
    If W[K] > WMAX THEN WMAX:=W[K];
  //dEFINE 'small'
  WMIN:=WMAX*0.1E-6;
  //Zero the 'small' singular values
  For K:=1 To N do
    If W[K] < WMIN THEN W[K]:=0;
  SVBKSB(U,W,V,N,N,B,X);
  Writeln(F, '計算出的方程組的解');
  For I:= 1 To N do
    Writeln(F,Format(s2,[X[I]]));
  Writeln(F, '將計算出的解乘以系數矩陣的結果');
  For I:=1 To N do
  begin
      B[I]:=0;
      For J:=1 To N do
      begin
        B[I]:=B[I] + A[I,J]*X[J];
      end;
  end;
  For I:= 1 To N do
    Writeln(F,Format(s1,[B[I]]));
  CloseFile(F);
  //屏幕顯示計算結果
  memo1.Lines.LoadFromFile('d:\delphi_shu\p1\d1r8.dat');
end;