How do I extract multiple vectors of different lengths from a single vector?

I have a noise signal generated from a power supply rail that crosses zero at about 118 points. I want to extract vectors of the data from one negative zero crossing to the next to separate them out. They are from a PRBS7 pattern and I want to make multiple patterns from the one pattern by randomizing the order of the vectors.

My initial attempt to extract the vectors (Doesn't work because they are different lengths)

*ivddx is the noise vector, v is the vector that contains the zero crossing indices of ivddx
k=length(v)
for i = 1:k
    if i==1
        a(:,1)=ivddx(1):ivddx(v(1));
    elseif i==k
        a(:,k+1)=ivddx(v(k):end);
    else
        a(:,i)=ivddx(v(i):v(i+1)-1);
    end
end

Answer 1

[Doug Hull]

You should store each extracted vector in a cell array. The elements of a cell array do not care if they are different lenths:

>> a{1} = [1]

a = 

      [1]

>> a{2} = [2 2]

a = 

      [1]    [1x2 double]

[Michael]

Thanks