I can store the zero matrix (=module morphism) $R^2\overset{a}{\leftarrow} R^3$ as a=SparseArray[{},{2,3}]
. But
- $R^0\overset{a}{\leftarrow} R^3$ stored as
a=SparseArray[{},{0,3}]
, - $R^2\overset{a}{\leftarrow} R^0$ stored as
a=SparseArray[{},{2,0}]
, - $R^0\overset{a}{\leftarrow} R^0$ stored as
a=SparseArray[{},{0,0}]
,
is no longer a SparseArray and contains no info about the dimensions of $a$. How can I remedy this?
{{}}
but 0x1 or similar is not possible (when a result would be this it usually gives us{}
, a length-0 1-index tensor). While this applies to non-sparse arrays, it seems that it's SparseArray data structure stays consistent with this. $\endgroup$ – Szabolcs Sep 4 '18 at 16:58