Code is basically done, minor problem

Hi, I have this script almost completely figured out (the specifics at least) but I can't get it to run. The error message is saying that the function can't be defined in this context. I believe it's because the function isn't supposed to be inside the script, but I'm not sure on exactly how to fix it. Do I just copy and paste the functions into a new script and save them as their own m-file? And if so what do I replace the function with in my real script?

Here's the script:

%%Part 1
clc;

clear all;

function [v,lambda]=powermat1([6 5;1 2],[0 1]',10) %%define matrix, vector, and loop
v =[0 1]' ;

A=[6 5;1 2];

for n = 1:10 %%setting the process for 1 to 10

     vnew = A*v;

lambda = norm(vnew,inf)/norm(v,inf);

fprintf('n = %4d, lambda = %g, v =[ %g %g ] \n', n, lambda, v');

v=vnew;

end

v = v/norm(v); %normalise x

fprintf('n = %4d ,normalised v = [%g %g ]\n', n, v')

%%Part 2
clc;

clear all;

A=[6 5;1 2];

[eigen_vector, eigen_value]=eig(A) %%checking answer

Answer 1

[Image Analyst]

Get rid of the script before of the function declaration. The script just does clear all, but it's still a script, and you can't have a script and function(s) all in the same m-file. Or else put

function myfunction

as the first line. Use whatever the m-filename is.

Answer 2

[Star Strider]

‘Do I just copy and paste the functions into a new script and save them as their own m-file?’

Yes! Spot on!

‘And if so what do I replace the function with in my real script?’

Call it just as you would any other external function:

[v,lambda]=powermat1([6 5;1 2],[0 1]',10)

You’ll probably have to experiment with them to get everything to work correctly, but that’s just part of the ongoing process of becoming a more skilled programmer. If you have problems you have trouble solving, describe your problem, post your code and any error messages, and you will get help here.

Answer 3

[Walter Roberson]

Remove the clc and clear all and save the resulting function in powermat1.m

[Walter Roberson]

function [v,lambda] = powermat1(A,v,maxn) %%define matrix, vector, and loop

for n = 1:maxn %%setting the process for 1 to 10
  vnew = A*v;
  lambda = norm(vnew,inf)/norm(v,inf);
  fprintf('n = %4d, lambda = %g, v =[ %g %g ] \n', n, lambda, v');
  v = vnew;
end