That's right. It is there as an additional knob when you need it. For large matrices where 32-bit indices suffice, this leads to useful space savings and should also have lower indexing overhead inside sparse solvers.
-viral On Thursday, July 10, 2014 7:32:26 AM UTC-7, Mauro wrote: > > It's the type of the index variables. So, potentially useful to save > some space by using Uint32 or Uint16 for them. Of course that reduces > the maximal size of the matrix. > > There is an "example" in test/sparse.jl: > S1290 = SparseMatrixCSC(3, 3, Uint8[1,1,1,1], Uint8[], Int64[]) > > I think you have to construct it with SparseMatrixCSC, as `sparse` just > uses Int. > > On Thu, 2014-07-10 at 13:52, Simon Byrne <[email protected]> wrote: > > Out of curiosity, what is the purpose of the Ti parameter in > > SparseMatrixCSC type? > > > > I managed to track down this old commit: > > > https://github.com/JuliaLang/julia/commit/a0961e5df69da9f736ac8cb54a1186433fa6c1ba > > > which suggests it was introduced in order to conserve space for small > > matrices, but now it seems to always be the default Int type. > > > > -simon > >
