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 trade-offs.
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 <[email protected]> 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 row-length x col-length, > the same as for RealMatrix. > > Thanks in advance! > > Raviv >
