Phil Steitz a écrit : > I noticed a breakage in one of my apps that uses > MatrixUtils#createRealMatrix(double[][], boolean). This method seems to > have been removed. I guess this is because DenseRealMatrix can't > support this. I understand the value of DenseRealMatrix, but I still > see value in the double[][]-backed RealMatrixImpl. Any objections if I > restore the method above, change the other factories to return > RealMatrixImpl instances as before and add createDenseMatrix() > methods? I would also be OK with deprecating the createRealMatrix() > methods and adding CreateXx methods for both versions.
I don't feel comfortable with this approach. The boolean parameter was merely an optimization feature avoiding a copy. However, it implicitely relied on one implementation only (RealMatrixImpl) and exposed an internal array. As far as I understood, the factory methods in MatrixUtils were used to hide the implementation. If they become implementation-specific, I don't see the added value for factory methods versus class constructors. Nevertheless, my concerns are minor ones. Feel free to bring these methods back if you consider there is a need for them. In the same spirit, I am currently testing another block layout using blocks size in a range rather than fixed size and recursive layout. This is roughly an implementation based on Chatterjee, Lebeck, Praveen and Thottethodi paper "Recursive Array Layouts and Fast Matrix Multiplication" (http://www.cs.duke.edu/~alvy/papers/matrix-tpds.pdf). If the performances are good, I will use this layout for DenseRealMatrix. Luc > > --------------------------------------------------------------------- > To unsubscribe, e-mail: dev-unsubscr...@commons.apache.org > For additional commands, e-mail: dev-h...@commons.apache.org > --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@commons.apache.org For additional commands, e-mail: dev-h...@commons.apache.org
