Count number of indexes for each consecutive values in column of array

I have an array of a variable of dimension: 23999 x 1

The array consists of 1s and 0s.

I want to count how many indexes each consecutive 1s take up. For example:

[0 0 1 1 1 0 0 0 0 0 1 1 1 1 1 1 1 1 1 0 0 0] (vertically of course)

the output I would like is 3 9

I tried using diff and find but keep getting the error horzcat... Can somebody help me?

Answer 1

[Stephen23]

>> V = [0 0 1 1 1 0 0 0 0 0 1 1 1 1 1 1 1 1 1 0 0 0];
>> D = diff([0;V(:);0]);
>> find(D<0)-find(D>0)
ans =
   3
   9

[gummiyummi]

thanks! works perfectly

[gummiyummi]

could you explain the annotation behind diff([0;V(:);0]) ?