Hello, I am a new, but fairly happy user of commons-math 1.2 and I have begun to use it in my code. I needed a sparse matrix implementation for some data analysis work I was doing, and unfortunately the code with RealMatrixImpl was coming back with an OOME. So I built a SparseRealMatrixImpl as a subclass of RealMatrixImpl, which uses a Map<Point,Double> as its backing store, storing only the non-zero entries. I would like to contribute this implementation back to the commons-math project.
I have opened a JIRA enhancement request MATH-230 with a patch against the 2.0 branch. Patch and detailed description of the changes are available here. http://issues.apache.org/jira/browse/MATH-230 I have also had to make some changes to RealMatrixImpl and LUDecompositionImpl, mainly replacing the data[][] references with RealMatrix.getEntry(i,j) calls to insulate the backing store from being accessed directly by calling code, and thus making it possible for subclasses to provide their own internal backing stores. Would appreciate if you folks can take a look and let me know if it is feasible to add this into the 2.0 release. That way I can continue using commons-math future versions without having to patch it after every upgrade. I noticed that there has been some previous discussion about sparse matrix support here: http://markmail.org/message/2k5dk4fbewdtn5rz so I sent a personal email to John Iacona asking him about about the code he speaks of here. But he is working on other things, and doesn't know when he will be able to check in his sparse matrix support changes. His approach is a little different from mine (he has a SparseMatrix interface, which is implemented by a SparseMatrixImpl). I considered that approach initially, but came to the conclusion that it would mean quite a bit of code duplication, which I wanted to avoid as far as possible. Thanks -sujit --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]