dividing a column matrix based on the no

i have a single column matrix A=0 0 0 1 1 1 1 0 0 0 0 2 2 2 2 0 0 0 0 now i have to divide this in to several matrices such whenever 0 changes to 1 or 2 i want a new matrix in this case A1= 1 1 1 1 0 0 0 0; A2=2 2 2 2 0 0 0 0 which are also single column matrices

Answer 1

[Oleg Komarov]

A = [0 0 0 1 1 1 1 0 0 0 0 2 2 2 2 0 0 0 0].';

Split sequence (transforming in string)

out = regexp(sprintf('%d',A) ,'(1+0+|2+0+)','match');

Convert to double and store in cell array

c = cellfun(@(x) x.'-'0',out,'un',0)
c{1} % to retrieve the value

Organize eventually in structure with dynamic fields A001, A002, ..., An

numC = numel(c);
s = cell2struct(c, reshape(sprintf('A%03d', 1:numC),4,[]).',numC);
s.A001 % to retrieve the value

EDITED

With a loop

A = [0 0 0 1 1 1 1 0 0 0 0 2 2 2 2 0 0 0 0].';
c = 0;  
s = 0;

% Start condition
if ismembc(A(1,1),1:2) 
   s = 1;
end
for n = 2:numel(A(:,1))-1
    if A(n,1) == 0 && ismembc(A(n+1,1),1:2)
        if s
            c = c+1;
            Out{c} = A(s:n,:);
        end
        s = n+1;
    end
end
% End condition
if s < n
    Out{c+1} = A(s:end,:);
end

[bilhan]

i am getting

cellfun(@(x) x.'-'0',out,'un',0)

ans =

[8x1 double] [8x1 double]

how could i retrieve those arrays

please send me a code using for loop

[Oleg Komarov]

See edit and search the documentation on how to operate with cell arrays or dynamic field indexing in structures

[bilhan]

thanks for your answer

but i want this done using a for loop

[Oleg Komarov]

You should have stated it in the first request.

[bilhan]

thank you very much

[bilhan]

now ia m getting

c{1}=1111 insyead of 11110000

[Oleg Komarov]

Do you use the same A? If not post the input array/vector.

Answer 2

[Andrei Bobrov]

more variant

A = A(:);
I = cumsum([0;diff(A)]~=0 & (A ~= 0));
out = arrayfun(@(x)A(I==x),1:max(I),'un',0);

same with the loop

A = A(:).';
I = cumsum([0,diff(A)]~=0 & (A ~= 0));
out = cell(1,max(I));
for j = 1:max(I),
   out{j} = A(j==I);
end

[bilhan]

thank you man thbats wonder ful perfect thats what i want.

[bilhan]

the same question but an extension if A is a two columned matrix and i want to divide it based on the first column same as above then

for eg:_

a=[0 0;0 1;1 1;1 0;0 1;0 0;0 1;2 0;2 1;0 0;0 1]

a1=[1 1;1 0;0 1;0 1]

a2=[2 0;2 1;0 0;0 1]

[Oleg Komarov]

I edited my solution to take into account initial conditions (if A doesn't start with a 0) and to split a matrix on the basis of the first array.

[bilhan]

thank you