i need a nested for loop

i need a nested for loop matlab pattern following this code :

1 
121 
12321
1234321
123454321

[Jan]

This sounds like a homework. It would not be useful if the forum solves your homework. So please post, what you have tried so far and ask a specific question.

Answer 1

[Andrei Bobrov]

ii = (1:5)';
out = arrayfun(@(ii)[1:ii,ii-1:-1:1],ii,'un',0);

or

n = 5;
A = [triu(ones(1,n).*(1:n)');flip(triu(ones(1,n).*(1:n)',1),1)];
t = A ~= 0;
B = zeros(n*2-1,n);
k = sort(t,'descend');
B(k(any(k,2),:)) = A(t);
out = B';

[salah berra]

not working very wrell

Answer 2

[Jan]

A "nested for loop" is accurate enough to start:

n = 5:
for i1 = 1:n
  for i2 = ???
    ...
  end
end

Now insert, what you want to appear. fprintf('%i', v) and fprintf('\n') will help.

[salah berra]

tell me exactly

[Walter Roberson]

You appear to be asking that someone gives you a complete answer to a homework question.

[Jan]

@salah berra: I assume also, that this is a homework question. Then posting a solution is to useful, because it would be cheating, if you submit it as your solution.

All you have to do is to replace the "???" in the inner loop by some meaningful limits, to insert "fprintf('%i', v')" with replacing the "v" by one of the loop indices, and a "fprintf('\n')" as a line break. Then you have the code for:

1
12
123
1234

But now it should be easy to get the trailing part of the lines also. Example:

for i3 = 4:-1:1
  disp(i3)
end

I'm convinced, that you are able to do this and then submit a solution written by your own.