element extraction from vector

[hassen62]

Hi the Octavers,
I would like to ask you: if we have a vector u of this form:
u=[1 0 0 0 0 -1 0 0 0 0 0 1]';
How we can construct a program that extract two vectors v and w from u, where 
the elements of v are 1 and -1, i.e v=[1,-1,1]', and the elements of w are the 
number of observations of the elements of v in u, i.e w=[1 6 12]'.
Many thanks in advance.
Hassen.


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