Matriks Tridiagonal pada Metode Numerik

Algoritma Program Pascal untuk Matriks Tridiagonal pada Metode Numerik

program Tridiagonal;

uses wincrt;

var

   i, j, k, n : integer;

   p          : real;

   a          : array[0..20] of real;

   b          : array[0..20] of real;

   c          : array[0..20] of real;

   d          : array[0..20] of real;

   e          : array[0..20,0..20] of real;

   x          : array[0..20] of real;

label 1, 2, 3, 4, 5;

begin

1:

  writeln('Orde matriks anda(maksimal 20x20): ');readln(n);

  {Penginputan elemen-elemen matriks}

  for i:= 1 to n do

      begin

           write('a',i,' = ');readln(a[i]);

      end;

  for i:= 1 to n-1 do

      begin

           write('b',i,' = ');readln(b[i]);

      end;

  for i:= 2 to n do

      begin

           write('c',i,' = ');readln(c[i]);

      end;

  for i:= 1 to n do

      begin

           write('d',i,' = ');readln(d[i]);

      end;

  {Pencetakan matriks tridiagonal}

  clrscr;

  writeln('Matriks anda:');

  for i:= 1 to n do

      begin

           e[i,i]:= a[i];

           e[i,i+1]:= b[i];

           e[i,i-1]:= c[i];

      end;

  for i:= 1 to n do

      begin

           write('|');

           for j:= 1 to n do

               begin

                    write(' ',e[i,j]:0:4);

               end;

           writeln(' ',d[i]:0:4,' |');

      end;

  writeln('');

  writeln('Akar-akarnya:');

  {Proses SPL tridiagonal}

  for i:= 1 to n-1 do

      begin

           p:= c[i+1]/a[i];

           a[i+1]:= a[i+1] - p*b[i];

           d[i+1]:= d[i+1] - p*d[i];

      end;

  x[n]:= d[n]/a[n];

  writeln('x',n,' = ',x[n]:0:4);

  for k:= n-1 downto 1 do

      begin

           x[k]:= (d[k]-b[k]*x[k+1])/a[k];

           writeln('x',k,' = ',x[k]:0:4);

      end;

end.


Preview Program: