implementation
//PROGRAM D1R9
//Driver for routine SPARSE
uses
  unit2;
  {$R *.DFM}
procedure ASUB(XIN:array of real;var XOUT:array of real);
var
   I,N:integer;
begin
    N:= 20;
    XOUT[1]:=XIN[1] + 2 * XIN[2];
    XOUT[N]:=-2 * XIN[N - 1] + XIN[N];
    For I:=2 To N - 1 do
        XOUT[I]:=-2 * XIN[I - 1] + XIN[I] + 2 * XIN[I + 1];
end;
procedure ATSUB(XIN:array of real;var XOUT:array of real);
var
   I,N:integer;
begin
    N:=20;
    XOUT[1]:=XIN[1] - 2 * XIN[2];
    XOUT[N]:=2 * XIN[N - 1] + XIN[N];
    For I:=2 To N - 1 do
        XOUT[I]:=2 * XIN[I - 1] + XIN[I] - 2 * XIN[I + 1];
end;

procedure TForm1.Button1Click(Sender: TObject);
var
    X,B,BCMP:Array[0..20] of real;
    I,J:Integer;   RSQ:real;
    F:TextFile;
const
    s1='%10.1f'; s2='%10.6f';  N = 20;
begin
  //輸入已知的方程組的系數(shù)矩陣
  For I:=1 To N do
  begin
      X[I]:= 0;
      B[I]:= 1;
  end;
  B[1]:= 3;
  B[N]:= -1;
  SPARSE(B,N,X,RSQ);
  //輸出計(jì)算結(jié)果到文件
  AssignFile(F, 'd:\delphi_shu\p1\d1r9.dat');
  Rewrite(F);
  Writeln(F,'Sum-squared residual:  ',Format(s2,[RSQ]));
  Writeln(F, '計(jì)算出的方程組的解');
  For I:= 1 To 4 do
      Writeln(F,Format(s2,[X[1+(I-1)*5]]),Format(s2,[X[2+(I-1)*5]]),
                 Format(s2,[X[3+(I-1)*5]]),Format(s2,[X[4+(I-1)*5]]),
                 Format(s2,[X[5+(I-1)*5]]));
  Writeln(F, '將計(jì)算出的解B乘以系數(shù)矩陣，以驗(yàn)證計(jì)算結(jié)果正確');
  ASUB(X,BCMP);
  Writeln(F, '解乘以系數(shù)矩陣','         方程組的右端向量');
  For I:=1 To N do
     Writeln(F,Format(s1,[BCMP[I]]),'           ',Format(s1,[B[I]]));
  CloseFile(F);
  //屏幕顯示計(jì)算結(jié)果
  memo1.Lines.LoadFromFile('d:\delphi_shu\p1\d1r9.dat');
end;