The number of consecutive ocurrances in an array

I have an array that is shown as: a=[0,0,1,1,1,0,0,1] and I would like to get the number of consecutive ocurrances in it along with the number itself meaning that I would like the output to be b=[2,0,3,1,2,0,1,1] where 0 occurred two consecutive times, 1 occurred three consecutive times, etc. Please help me and thank you in advance.

[Image Analyst]

I have no idea what this means. So 0 occurred in 2 groups - okay, fine. 1 occurred 3 times??? It's there 4 times in 2 separate groups, so how do you get 3? And why is the 3 in the third element whereas 0 was in the first element?

And what does "etc." mean? Like 2 occurred ? times, 3 occurred ? times, ..... 7 occurred ? times? But the problem is no other numbers other than 0 and 1 occur at all. So what does "etc." mean?

[John Chilleri]

The b is a description of vector a:

Two 0s, then three 1s, then two 0s, then one 1.

[Stephen23]

@Image Analyst: run length encoding.

Answer 1

[Guillaume]

This is trivially achieved with diff and find:

a = [0, 0, 1, 1, 1, 0, 0, 1];
transitions = find(diff(a));
runlengths = diff([0, transitions, numel(a)]);
runvalues = a([transitions, end]);
valuelength = reshape([runlengths; runvalues], 1, [])

[Stephen23]

+1 Nice and simple. That is the way to do it.