Code for Gaussian Elimination

[XodoX]

I have this code for a Gaussian Elimination:

clear all
close all
%A=[1,1,1;1,-2,2;1,2,-1]
%B=[0;4;2];

A=[2,1,-1,4,2,5;-3,-1,2,5,9,4;-2,1,2,6,6,3;1,2,3,5,4,6;8,9,4,4,1,3;2,3,5,1,9,7]
B=[8;-11;-3;5;7;8]

%A=[1,0,0;1,0,0;1,0,0]
%B=[1;1;1];

% SET UP COUNTERS
COUNTER_AMS=0
COUNTER_DIVISION=0

% GET SIZE OF MATRIX
N=size(A,1);

for k=1:N-1
i_test=k;
CONDITION=0;
SINGULAR_MATRIX=0;

while CONDITION==0
if (A(i_test,k)~=0)
CONDITION=1;
i=i_test;
else
i_test=i_test+1;
COUNTER_AMS=COUNTER_AMS+1;
end

if i_test>N
'ERROR MATRIX NON SINGULAR'
pause
%exit
end
end

% PERMUTE RAW IF i different then k
if i~=k
TEMP=A(i,:);
A(i,:)=A(k,:);
A(k,:)=TEMP;

TEMP=B(i);
B(i)=B(k);
B(k)=TEMP;
end


for j=k+1:N
p_jk=A(j,k)/A(k,k);
COUNTER_DIVISION=COUNTER_DIVISION+1;

A(j,:)=A(j,:)-p_jk*A(k,:);
B(j)=B(j)-p_jk*B(k);
COUNTER_AMS=COUNTER_AMS+4;
end
end

if A(N,N)==0
'MATRIX SINGULAR'
pause
%exit
end% ALGORITHM OF BACKWARD SUBSTITUTION
X(N)=B(N)/A(N,N);
COUNTER_DIVISION=COUNTER_DIVISION+1;

for i=N-1:-1:1
SUM=0;
for j=i+1:N
SUM=SUM+A(i,j)*X(j);
COUNTER_AMS=COUNTER_AMS+2;
end
X(i)=(B(i)-SUM)/A(i,i);
COUNTER_AMS=COUNTER_AMS+1;
COUNTER_DIVISION=COUNTER_DIVISION+1;
endX'

COUNTER_AMS
COUNTER_DIVISION
N*(N+1)/2
N^3+N^2-5*N/6

As you can see, the input is A and b. I'm trying to figure out how I can make this code work for this Gaussian Elimination:

http://img189.imageshack.us/f/50468910.png/

It's 17 rows. The code can do 17 rows. But some of the equations aren't in the correct format. Like line 4: F3-10=0 will has to be F3=10. You need to move the 10. You have to move it to the right side to make it part of your b. A is the left side. It's only a few lines, the rest remains 0. You just type and define A as your 17 by 17 matrix inside the code and your B as the B that you ended up with.
Does anybody know how I make this work with this code? I'm not sure what I have to exactly change here! That's a MATLAB code, but it's not much different.

 

[Future Bruno]

You need to reformat the equations into the standard form Ax=b. This means you will have to move all constants to the right side of the equation and set them equal to 0. For example, for line 4, you would have F3-10=0 which would become F3=10. Once you have all of your equations in the correct format, you can enter the A matrix and b vector into the code.