unify CSRLinear, CSCLinear, COOLinear using SparseLinear
#256
| Job | Run time |
|---|---|
| 2m 8s | |
| 1m 47s | |
| 2m 56s | |
| 2m 10s | |
| 1m 43s | |
| 3m 14s | |
| 2m 15s | |
| 3m 10s | |
| 2m 17s | |
| 4m 30s | |
| 2m 33s | |
| 28m 43s |