Kim van der Linde wrote:
> Hi Phil,
>
> I have been thinking for a few days on the Matrix classes.
>
> I think the Matrix class itself should contain all those methods that do
> matrix calculations (add, subtract, multiply) that either a Matrix
> themselfs or proporties of the Matrix (isSingular for example).
I agree.
The mean
> methods (getRowMeans) etc are statistics done ON a matrix, and I think
> they should be in a seperate class, maybe called MatrixStats. This
> enables aso he option to add variances and SD's which are needed for
> column mean resp meanSD standardizations, to be used for example in PCA
> calculations when a covariance resp. correlation matrix is used.
I agree here as well. Do you see use cases where you will want to start
with a double[][] array, perform matrix operations on it (say some
decomposition) and then run stats on the resulting matrix? Will it be too
onerous to make copies of the double[][] at each stage? If so, we need to
think about access to the double[][].
>
> Is there the intention to add an EigenvalueDecomposition class to the
> package? In that case, which algorithm is targeted to be used? Jacobi?
We have not discussed this. Feel free to add to the wish list and propose
an algorithm. We also need to discuss how best to implement the strategy
pattern for decompositions in general, as there will often be multiple
algorithms to choose from.
Phil
>
> Cheers,
>
> Kim

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