count a sequence of 1 or 0

Hi

I have the following data (2 column, A and B) imported from Excel:

A B

0 0

0 1

1 1

1 0

1 1

1 0

0 1

1 1

0 1

0 1

I want to count the repeat of 0 and 1 in sequence for column A. I do not want to count all 1 or all 0. Next, based on this count, I want to count only 0 on column B for same sequence.

I expect the following result:

2 1

4 2

1 0

1 0

2 0

Answer 1

[Stephen23]

>> M = [0,0;0,1;1,1;1,0;1,1;1,0;0,1;1,1;0,1;0,1]
M =
   0   0
   0   1
   1   1
   1   0
   1   1
   1   0
   0   1
   1   1
   0   1
   0   1
>> X = [true;diff(M(:,1))~=0];
>> Y = diff(find([X;true]));
>> V = accumarray(cumsum(X),~M(:,2));
>> Z = [Y,V]
Z =
   2   1
   4   2
   1   0
   1   0
   2   0

[Boby S]

Dear Stephen

I want to exclude the first row of second column on each repeated sequence (underlined and bold) from my results(for sure zero ones)? This exclusion is for more than one repeat. One repeats stays without change. Do you have any idea?

New example:

0 0

0 1

1 0

1 0

1 1

1 0

0 1

1 1

0 1

0 0

I would like to have results like this?

2 0

4 2

1 0

1 0

2 1

[Stephen23]

Generate X and Y, then do this:

>> F = @(v)sum(v(1+(numel(v)>1):end));
>> V = accumarray(cumsum(X),~M(:,2),[],F);
>> Z = [Y,V]
Z =
   2   0
   4   2
   1   0
   1   0
   2   1

[Boby S]

Thank you