ndr.data.colvec

  COLVEC - return a matrix reshaped as a column vector

   Y = ndr.data.colvec(X)

   Returns the contents of the matrix X as a column vector Y that is 1xM,
   where M is the product of all the sizes of the dimensions of X
   (M = PROD(SIZE(X))).

   ndr.data.colvec is equivalent to Y = X(:);

   This function is useful for addressing all of the elements of a matrix
   as a vector when X is a subset of another matrix.

   See also: ndr.data.rowvec

   Example: 
     A = rand(5,5)
     Y = ndr.data.colvec(A(1:3,1:2)) % returns points in rows 1:3, columns 1:2