How to fix this problem?

>> sitem
sitem =
     1     2     3
>> U
U =
  1×2 cell array
    [1×2 double]    [1×2 double]
U{1}
ans =
     1     2
>> U{2}
ans =
     2     3

I want to check each value of sitem if it contain in U an put them in F ={}

the output is F = { {1 2}, {{1 2 },{ 2 3 }}, {2 3} }

please help me

[Image Analyst]

Have you read the FAQ on cell arrays: Click Here

So what you're saying is that F is a cell array with 3 cells in it. Each cell contains another cell array - a 1-by-2 cell array. And the cell in the second cell F{2} contains 2 cells, each of which is ALSO a cell array. And... well it just gets so complicated to describe so let's just run it and see what F really is:

F = { {1 2}, {{1 2 },{ 2 3 }}, {2 3} }
celldisp(F)

You'll see

F =
  1×3 cell array
    {1×2 cell}    {1×2 cell}    {1×2 cell}
F{1}{1} =
     1
F{1}{2} =
     2
F{2}{1}{1} =
     1
F{2}{1}{2} =
     2
F{2}{2}{1} =
     2
F{2}{2}{2} =
     3
F{3}{1} =
     2
F{3}{2} =
     3

Why on earth do you want that? Cell arrays of cell arrays of cell arrays nested three deep? What an absolute nightmare. Why don't you just use ismember() to see if some value is contained in the array you want to search?

[Mira le]

that not what I meant

I said before I have to check each value of sitem if it contains in U

for example;

a=1;
  for i=1:length(sitem)
     for j=1:length(U)   
          if ismember(sitem(i),U{j})
              F{a } = [F U{j}];
         end
    end
     a=a+1;
end