search through an array for patterns and put into cell arrays.

Looking to search through a large array of integers and find patterns of up to 1-10 ( can be 1 or 1 2 3 or 1 2 3 4 5 6 .. 10, etc) and place those into cell arrays. Resulting multiple cell arrays of different lengths. A is really long so I was hoping to avoid lengthy loops, in which I figured out a way using ismember and a very very long inefficient loop.

I do not know how many patterns of 1-10 exist. Is this possible? Thanks.

if true
  A = [ 1 2 3 78 28 92 1 76 89 23 87 1 2 3 4 5 6 7 8 9 10 72 91 72]
  result{1} = {1 2 3}
  result{2} = {1}
  result{3} = {1 2 3 4 5 6 7 8 9 10}

end

Answer 1

[Kelly Kearney]

This sort of problem can usually be solved by using a various combinations of diff:

A = [ 1 2 3 78 28 92 1 76 89 90 23 87 1 2 3 4 5 6 7 8 9 10 72 91 72];

(I modified your example by one element to add a run that didn't start with 1, just in case...)

isnew = [true ~(diff(A) == 1)];  % is each elemet 1 greater than previous?
sidx = find(isnew);              % indices of start of each run
nper = diff([sidx length(A)+1]); % number of elements in each run
is1 = A(sidx) == 1;              % does run start with 1?

consec = mat2cell(A, 1, nper);   % break matrix into cells of runs
consec1 = consec(is1);           % keep only cells starting with 1

Result:

>> consec1{:}

ans =

       1     2     3

ans =

       1

ans =

       1     2     3     4     5     6     7     8     9    10