Code covered by the BSD License

# Numerical Methods Using MATLAB, 3e

### John Mathews (view profile)

20 Aug 2002 (Updated )

Companion Software

seidel(G,P,delta, max1)
```function [P,iter]= seidel(G,P,delta, max1)

%Input  -  G is the nonlinear system saved in the M-file G.m
%       -  P is the initial guess at the solution
%       -  delta is the error bound
%       - max1 is the number of iterations
%Output - P is the seidel approximation to the solution
%     	- iter is the number of iterations required

% NUMERICAL METHODS: MATLAB Programs
%(c) 1999 by John H. Mathews and Kurtis D. Fink
%To accompany the textbook:
%NUMERICAL METHODS Using MATLAB,
%by John H. Mathews and Kurtis D. Fink
%ISBN 0-13-270042-5, (c) 1999
%PRENTICE HALL, INC.

N=length(P);

for k=1:max1
X=P;

% X is the kth approximation to the solution
for j=1:N
A=feval('G',X);
% Update the terms of X as they are calculated
X(j)=A(j);
end

err=abs(norm(X-P));
relerr=err/(norm(X)+eps);
P=X;
iter=k;
if (err<delta)|(relerr<delta)
break
end
end

```