counting the number of times a number appears next to the same one in a row?

3 views (last 30 days)
Hi everyone,
I am trying to generate a random sequence and for this I have a row vector, which contains the values 1 to 6 in a random order 4 times (so my vector has 24 elements). I need a way to find how many times the same number appears next to the same number - I have a hard time explaining what I mean but here is an example:
1 2 3 4 5 6 -- no same number appears next to the same number so answer should be 0
1 1 2 3 4 5 -- here 1 is repeated once, so answer should be 1
1 1 2 3 4 4 - here 1 and 4 are repeated and so the answer should be 2
  3 Comments

Sign in to comment.

Answers (4)

madhan ravi
madhan ravi on 22 Jun 2019
Simpler:
nnz(~diff(vector))
Note: Taking into account that we only deal with integers.
  5 Comments

Sign in to comment.


KALYAN ACHARJYA
KALYAN ACHARJYA on 22 Jun 2019
Edited: KALYAN ACHARJYA on 22 Jun 2019
num=[1 2 3 4 5 6]; % Change this one and test
uniq_num=unique(num);
digit_repeat=length(num)-length(uniq_num)
Its works right?

Bruno Luong
Bruno Luong on 22 Jun 2019
Edited: Bruno Luong on 22 Jun 2019
>> A=[1 1 1 2 3 4 4 2]
A =
1 1 1 2 3 4 4 2
>> sum(diff(A)==0 & diff([NaN, A(1:end-1)])~=0)
ans =
2
>>

Kilian Liss
Kilian Liss on 22 Jun 2019
Probably not the most ellegant solution, but the following code seems to work:
x1 = [1 1 2 3 4 4];
count = 0;
for i = 1:length(x1) - 1
if(x1(i) == x1(i + 1))
count = count + 1;
end
end

Categories

Find more on MATLAB in Help Center and File Exchange

Tags

Community Treasure Hunt

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

Start Hunting!