## Gauss-Seidel Method (Matlab)

I need to solve the following problem using Matlab

This is my code so far:

Code:
clear all
clc
clf
function x=GaussSeidel(A,b,y,N)
n = length(y);
for k = 1:N
for i=1:n
s=b(i);
for j =1:i-1
s=s-A(i,j)*y(j);
end
for j = i+1:n
s=s-A(i,j)*y(j);
end
x(i)=s/A(i,i);
x(i)=x(k);
end
y = x'
end
But I keep getting the following error:

Code:
Error: File: Untitled.m Line: 4 Column: 1
Function definitions are not permitted in this context.
Why am I getting this error? What do I need to do?

And my inputs would be:

Code:
A=[-5 0 2 0 -1 ;
0 9 0 3 0 ;
2 0 5 0 2 ;
0 -2 0 4 0 ;
-1 0 7 0 7]
b = [8;4;-8;-4;0]
x0=[8;4;-8;-4;0]
For N, how do I know many iterates N are necessary for this problem?

Any help with the code is greatly appreciated.

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 Blog Entries: 9 Recognitions: Gold Member You're defining a function in a script file. In MATLAB, functions are defined in a separate file with the same name as the function. Create a file GaussSeidel.m with the following: Code: functionx=GaussSeidel(A,b,y,N) n = length(y); for k = 1:N for i=1:n s=b(i); for j =1:i-1 s=s-A(i,j)*y(j); end for j = i+1:n s=s-A(i,j)*y(j); end x(i)=s/A(i,i); x(i)=x(k); end y = x' end and a script file that calls the function.
 I'm not familiar with matlab, but I believe this is an incorrect implementation of the Gauss-Seidel method. This looks like the Jacobi method to me. I'm going to fool around with this and get back.