i want to put n and counter in one matrix

for n=4:50

a=[];

e = ones(n,1);

A1 = spdiags([-e 0*e -e 4*e -e 0*e -e],-3:3,n,n);

full(A1);

A=full(A1);

b=zeros(n,1);

b(1)=1; b(end)=1;

x=zeros(n,1);

L=tril(A,-1);

U=triu(A,1);

D=diag(A);

B=-1./D.*(L+U);

c=(1./D).*b;

flag=0;

counter=0;

epsilon=10^(-3);

while flag==0

counter=counter+1;

if counter>100000

error('too much')

end

x_new=B*x+c;

if max(abs((x_new-x)./x_new))<epsilon

flag=1;

end

x=x_new;

end

fprintf('%g %g\n',counter,n)

end

Answer 1

[Abhishek Gupta]

Hi,

As per my understanding, you want to create a matrix containing 'n' and 'counter' variables. One can do this task by appending a row, containing 'n' and 'counter' variables, at the end of the matrix on every iteration of the loop.

out = [];   % output matrix 
for n = 4:50
    % Your Code Here %
    
    out = [out; [n, counter]];  % append row containing n and counter 
end

Also, referring you to the following link for more information: -

https://www.mathworks.com/matlabcentral/answers/113813-append-rows-at-the-end-of-matrix