Join repeated continuous elements of a vector

Hi, is there a simple method to join repeated continuous elements of a vector in Matlab?

For example if the input is:

in = [1 1 1 2 2 3 6 6 6 1 1 1 4 4 4 2 2 2 6 4 4]

how can i get

out = [1 2 6 1 4 2 6 4]

Note that since 3 is not repeted, it is not in 'out' vector. Same for the only 6.

thanks !

[Walter Roberson]

No, there is no simple method. There are some methods that take a few lines.

[Alexander]

Thank you !

Answer 1

[Are Mjaavatten]

in = [1 1 1 2 2 3 6 6 6 1 1 1 4 4 4 2 2 2 6 4 4];
i = 1;
count = 1;
out = [];
a = in(1);
while i < length(in)
  i = i+1;
  if in(i) ~= a
     count = 1;
     a = in(i);
  else
    count = count + 1;
  end
  if count == 2;
     out = [out,a];
  end
end
disp(out)

[Alexander]

Thanks for your time

Your code works just fine !

This one works too:

in = [1 1 1 2 2 3 6 6 6 1 1 1 4 4 4 2 2 2 6 4 4];

BB=diff(find(diff(in)~=0));
in(diff(m)==0) = [];
in(find(BB==1)+1)=[];

out = in;