unit Unit2;

interface
uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls,unit1, Forms, Dialogs;
procedure CHOBSB(A:MATRX2; N:integer; D:array of real;var B:array of real);
procedure CHODCM(A:matrx2; N:integer;var D:array of real; T:array of real);
implementation
procedure CHOBSB(A:MATRX2; N:integer; D:array of real;var B:array of real);
var
    I,J:integer;  SUM:real;
begin
    For I:=1 To N do
    begin
        Sum:=B[I];
        For J:=1 To I - 1 do
            Sum:=Sum - A[I, J] * B[J];
        B[I]:=Sum;
    end;
    For I:=N DownTo 1 do
    begin
        If D[I] = 0 Then
        begin
            ShowMessage('Singular Matrix');
            Exit;
        end
        Else
            Sum:=B[I] / D[I];
        For J:=I + 1 To N do
            Sum:=Sum - A[J, I] * B[J];
        B[I]:=Sum;
    end;
end;

procedure CHODCM(A:matrx2; N:integer;var D:array of real; T:array of real);
var
    I,J,K:integer;  SUM:real;
begin
    For I:=1 To N do
    begin
        Sum:=A[I, I];
        For J:=1 To I - 1 do
        begin
            T[J]:=A[J, I];
            For K:=1 To J - 1 do
                T[J]:=T[J] - T[K] * A[J, K];
            If D[J] = 0 Then
            begin
                If T[J] <> 0 Then
                    ShowMessage('No Cholesky decomposition')
                Else
                    A[I, J]:=1;
            end
            Else
                A[I, J]:=T[J] / D[J];
            Sum:=Sum - T[J] * A[I, J];
        end;
        D[I]:=Sum;
    end;
end;
end.