cases the lambda vector is required in order for a symmetric Kruskal decomposition to exist, e.g. when a symmetric Kruskal tensor has an even number of components and the tensor to be decomposed has a negative element on its main diagonal. In many other cases, the lambda vector is optional and the symmetric Kruskal decomposition can be represented without specifying a lambda vector.</p><p>The <tt>symktensor</tt> class stores symmetric Kruskal tensors, and exploits the extra symmetric structure to perform ma