Apache Mahout also has a matrix package with sparse matrix support. In
particular, iterateNonZero is supported and there are multiple sparse
vector/matrix formats that provide different performance tradeoffs.
Our purpose is not necessarily to be a general purpose math package and the
system is still somewhat in flux so there is a good chance that Mahout Math
isn't what you need. On the other hand, because Mahout is much less mature,
changes are much easier to push through. Commons Math has a fairly strict
back compatibility policy that means that changes such as you want can take
a very long time even for trunk.
On Tue, Aug 17, 2010 at 5:49 AM, Raviv Granot <raviv.granot@gmail.com>
wrote:
> Hi,
> I see 2 implementations of sparse matrix in the math.commons.linear
> library.
>
> 1. OpenMapRealMatrix
> 2. SparseFieldMatrix
> Both are documented as "Sparse matrix implementation based on an open
> addressed map".
> Does anyone know what are the differences between the two? also, which
> method should I use to iterate only
> over the non zero elements? it seems that the WalkInRawOrder method runs
> over the entire rowlength x collength,
> the same as for RealMatrix.
>
> Thanks in advance!
>
> Raviv
>
