How do I extract consecutive numbers from a matrix?

2 views (last 30 days)
I have a matrix like: A=[1 2 5 6 7 8 9 20 21 22 23…] I'd like to separate consecutive number, like: C=[1 2] D=[5 6 7 8 9], E=[ 20 21 22 23]

Accepted Answer

Cedric
Cedric on 24 Jun 2014
Edited: Cedric on 24 Jun 2014
Here is a solution, but there are many ways to do it, some simpler than others:
grouped = mat2cell( A, 1, diff( [0, find(diff(A) ~= 1), length(A)] )) ;
where grouped is a cell array with the following content
>> grouped{1}
ans =
1 2
>> grouped{2}
ans =
5 6 7 8 9
>> grouped{3}
ans =
20 21 22 23
Edit : here is a funny way for Star Strider, who wanted a tutorial about ACCUMARRAY ;-)
grouped = accumarray( cumsum([1, diff(A) ~= 1]).', A, [], @(x){x} ) ;
  3 Comments
Cedric
Cedric on 24 Jun 2014
I was actually unaware that ACCUMARRAY could output cell arrays until I learned that from one of Andrei's solutions that blew my mind away.
Carlene Horner
Carlene Horner on 18 Jun 2019
I keep getting a horzcat error. I'm assuming this is because when finding the difference of a vector, the length of that difference vector is one less of the original vector. How do you fix this? Thanks!

Sign in to comment.

More Answers (0)

Categories

Find more on Tables in Help Center and File Exchange

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!