Group array in a cell according to their size

Hi everyone!

I've got a cell wich contains array like this : A={[1 2 3 4] [4 5 6 9] [1 2 3] [7 8 9] [1 2] [3 4]}

and I would like to group the arrays in this cell according to their size and get the indexes where they have been found in A and have the following result :

expected_result={{[1 2 3 4] [4 5 6 9]} {[1 2 3] [7 8 9]} {[1 2] [3 4]}}

idx_in_A={[1 2] [3 4] [5 6]}

Thanks in advance

Answer 1

[Thiago Henrique Gomes Lobato]

A direct implementation could be done like this:

A={[1 2 3 4] [4 5 6 9] [1 2 3] [7 8 9] [1 2] [3 4]};
sizes= [];

for idx=1:length(A)
    Vsize = length(A{idx});
    if ~ismember(Vsize,sizes)
        sizes = [sizes,Vsize];
        Pos = find(ismember(sizes,Vsize));
        idx_in_A{Pos} = idx;
    else
        Pos = find(ismember(sizes,Vsize));
        idx_in_A{Pos} = [idx_in_A{Pos},idx];   
    end
end
expected_result = cell(length(idx_in_A),1);
for idx= 1:length(idx_in_A)
expected_result{idx} = {A{idx_in_A{idx}}};
end

[kix]

thank you !

Answer 2

[Sumeet Singh]

You can use one containers.Map to group same sized arrays and another for storing the indices.

[kix]

Thank you !