It is not due to the spec. It is rather due to the common usage of XQUERY, forcing vendor solutions (as BaseX) to focus primarily on XML Data Base requests more than algorithmic performances.
There are actually some threads that are discussing these performance issues in the context of maps (maps are for instance used for sparse matrix representations) : look for instance to ""map module for XQUERY ?" that I initiated or "Higher-order XQuery Modules" by Leo from BaseX, on talk@ x-query.com mailing list. Anyhow, to write a serious linear algebra modulus, the basic need is to have a vector containers. Unfortunately, XQUERY does not provide any performant vector containers at present time, and it is not possible to code them in pure XQUERY : I have tried, and more experienced xquery developpers than me have also tried, without success. We have to wait for the XQUERY version that will give us these containers, a decision to be taken by the W3C. 2013/12/31 Andrew Welch <[email protected]> > > Are you saying the spec as it stands somehow forces all implementations to > be 1000x slower, or just what you have observed in some particular > implementation? > > > On 31 Dec 2013 14:27, "jean-marc Mercier" <[email protected]> > wrote: > > > > As far as I understand, you want to write a linear algebra module using > XQUERY ? > > If so, I opened a thread some months ago about this idea. My opinion > today is that this is a false good idea at present time. > > > > 1) XQUERY would be really good for writing concise, efficient linear > algebra modulus. > > 2) However, I strongly recommend to wait a little bit for starting > coding : the current version of XQUERY (3.0) suffers from performance > issues. A linear algebra modulus written in XQUERY is expected to have > performances performances 1000 X slower than its corresponding C++ or JAVA > (you can measure it precisely). Any mathematician linear algebra modulus > would probably trashed your modulus after the first test. > > > > Hope this helps > > > > > > > > 2013/12/31 Ihe Onwuka <[email protected]> > >> > >> Assuming a sparse representation it is about 4 lines of SQL. This is > known not least because you can read enough articles and papers that > discuss it and it optimises well. The obvious google search does not reveal > any corresponding XQuery discussion, neither does it appear to have > surfaced on this or the eXist mailing list (allowing for my deficient > search skills). For something so "trivial" I thought that was rather > strange. Hence I thought it would be prudent to ask before naively > embarking on a 600k X 40k matrix multiplication. > >> > >> > >> > >> On Tue, Dec 31, 2013 at 11:31 AM, Andrew Welch < > [email protected]> wrote: > >>> > >>> > >>> It should be pretty trivial... > >>> > >>> On 31 Dec 2013 11:07, "Ihe Onwuka" <[email protected]> wrote: > >>> > > >>> > Has anybody tried this in XQuery or if I am so foolish (not yet but > give me time) would I be the courageous <culturalReference> > http://www.youtube.com/watch?v=ik8JT2S-kBE</culturalReference> early > adopter. > >>> > > >>> > > >>> > _______________________________________________ > >>> > [email protected] > >>> > http://x-query.com/mailman/listinfo/talk > >> > >> > >> > >> _______________________________________________ > >> [email protected] > >> http://x-query.com/mailman/listinfo/talk > > > > >
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