1 | initial version |

Instead of converting sparse matrices to lists, try converting them to dictionaries.

```
M = MatrixSpace(QQ,10,10, sparse=True)
L = [M.random_element() for i in range(10)] # my starting list of matrices
W = VectorSpace(QQ, 100, sparse=True)
LL = [] # will be new list of sparse vectors
for m in L:
newdict = {}
mdict = m.dict()
for (i,j) in mdict:
# convert matrix dictionary indexed by (i,j) to vector dictionary indexed by 10*i+j
newdict[10*i+j] = mdict[i,j]
LL.append(W(newdict))
W.subspace(LL) # vector subspace of WW
```

In a perfect world, the following would work:

```
M = MatrixSpace(QQ,10,10, sparse=True)
L = [M.random_element() for i in range(10)] # my starting list of matrices
M.submodule(L)
```

but when I try it, it raises an error.

Copyright Sage, 2010. Some rights reserved under creative commons license. Content on this site is licensed under a Creative Commons Attribution Share Alike 3.0 license.