# create sub arrays from a array

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Ricky on 5 Jun 2013
Hello Everyone,
I am new to MATLAB so I am asking a very basic question which I am not able to solve.
I have an array of diemensions 672*9 , I want to create smaller arrays by comapring the value of column 9 only.
So for example my values in column 9 are
4
4
4
3.5
3
3.1
3.2
4
3.5
I specify the threshold value as 3.4 . So as my values in first 4 rows is more than 3.4 I store them in a new array. Then next 3 values in second array and finally last 2 values in third array.
I hope I have framed the question properly.

Azzi Abdelmalek on 5 Jun 2013
Edited: Azzi Abdelmalek on 5 Jun 2013
Edit
a=[4,4,4,3.5,3,3.1,3.2,4,3.5];
idx=a>=3.4;
idx2=sort([strfind(idx,[true false]) strfind(idx,[false,true]) numel(a)]);
idx1=[1 idx2(1:end-1)+1];
% pre-allocate;
y=cell(1,numel(idx));
for k=1:numel(idx1)
y{k}=a(idx1(k):idx2(k));
end
y{1}
y{2}
y{3}
Ricky on 5 Jun 2013
@Jan Simon : Sorry I misunderstood the solution it works for me now.

Andrei Bobrov on 6 Jun 2013
a=[4,4,4,3.5,3,3.1,3.2,4,3.5];
out = accumarray(cumsum([true; diff(a(:) > 3.4)~=0]),a(:),[],@(x){x});