Gauss or Gauss Jordan elimination

[Jakub_2]

Hello guy,
is here someone who can help me with programme about Gauss or Gauss Jordan elimination? I need it for calculating of system with linear equations.

Thank you

[gusano79]

What kind of help do you need? Problems with the algorithm? Locating/using a library?

[Jakub_2]

Help with the algorithm..

[gusano79]

Alright, have you tried writing any code yet? If so, please post it.

Starting at the beginning: How are you representing matrices?

[Jakub_2]

I have procedure which takes data from a file and writes them then I have problem with main procedure of Gauss :/ I will post it tomorrow now I need to go sleep gn :)

[Jakub_2]

Ok I found I did it bad... Now Im trying to do it right just have 2 days for it... Any help will 100% help me with it..

[Jakub_2]

I actually did that but Im not sure if its 100% right..

program gauss;
uses crt;
const max=10;
type matrix = array[1..max,1..max] of real;
var a:matrix;
    i,j,f,g,e,N,M:integer;
    y:real;
    c,d:boolean;
    inFile : text;
    inFileName : string;

procedure readFile(var A : matrix); 
  var i,j : integer;
   begin  i := 1; j := 1;
     while not eof(inFile) do
     begin 
        j := 1;
       while not eoln(inFile) do
         begin
           read(inFile,a[i,j]);
           inc(j);
         end;
         readln(inFile);
         inc(i);
     end;
     close(inFile);
   end;

procedure zero (m:integer; var A:matrix);
  var n,k:integer;
      z:real;
begin
  n:=m;k:=m;
  while (A[m,n]=0) and (M<=N) do   
    begin
      m:=m+1;
      if A[m,n]<>0 then          
        for n:=1 to N+1 do
          begin
            z:=A[m,n];           
            A[m,n]:=A[k,n];
            A[k,n]:=z;
          end;
    end;
end;

begin
writeln('Name of the input file?: ');
 readln(inFileName);
 assign(inFile,inFileName);
 reset(inFile);
 readln(inFile,N,M);
  d:=false;
  readFile(a);               
  for i:=1 to N-1 do
    begin
      zero(i,a);           
      for e:=1 to N-i do
        begin
          if a[i+e,i]<>0 then
            begin
              y:=a[i+e,i]/a[i,i]*(-1);   
                for j:=1 to n+1 do
                  begin
                    a[i,j]:=a[i,j]*y;
                    a[i+e,j]:=a[i+e,j]+a[i,j];
                  end;
            end;
        end;
      for f:=i to n do   
       begin
         c:=false;
         for g:=1 to N do c:=(a[f,g]<>0) or c;
          if not(c) then d:=a[f,N+1]=0;
       end;
    end;
    if c then
    begin
      for j:=n downto 1 do
        begin
          for e:=j+1 to n do a[j,N+1]:=a[j,N+1]-a[j,e]; 
          a[N+1,j]:=a[j,N+1]/a[j,j];                   
          for i:=1 to j-1 do a[i,j]:=a[i,j]*a[N+1,j]; 
        end;
      for j:=1 to n do
      writeln('x',j,'= ',a[N+1,j]:4:2);         
    end
       else if d then writeln('The equation has infinitely solutions !')
                 else writeln('The equation has no solution !');
  repeat until keypressed;
end.