Hi all, I've tried the following JSON query with zorba, mimicking a NxN, with N=200, matrix multiplications. Time is 10 sec on http://try.zorba.io/, behaving with a cubic N^3 complexitity. Do you really want to know what are the performances of standard linear algebra library for such matrix multiplications ?
import module namespace datetime = " http://www.zorba-xquery.com/modules/datetime";; declare variable $size := 200; declare variable $A := [ for $i in 1 to $size return [ for $j in 1 to $size return $i*$size+$j ] ]; let $R := ( datetime:current-time(), [ for $i in 1 to count(jn:members($A)) return [ for $k in 1 to count(jn:members($A)) return fn:sum( for $j in 1 to count(jn:members($A)) return $A($i)($j) * $A($j)($k) ) ] ] , datetime:current-time() ) return $R[count($R)] - $R[1] 2014-02-03 David Carlisle <[email protected]>: > On 03/02/2014 10:56, Hermann Stamm-Wilbrandt wrote: > >> PT1.713634S (JSONiq) versus PT9.77805S (XQuery) >> > > > ooh interesting , I wonder where the bottleneck in the xquery is. > Probably as Michael commented at some point earlier in the thread, the > time to access the ith element of a sequence $a[$i]. > > > But the language doesn't _need_ to change, just if more people did it > the xquery compilers would perhaps look out for sequences that are > exclusively accessed via numeric filters and implement them in a way > that gives constant time access. Having a separate array type does give > them a big hint though:-) > > David > > > ________________________________________________________________________ > The Numerical Algorithms Group Ltd is a company registered in England > and Wales with company number 1249803. The registered office is: > Wilkinson House, Jordan Hill Road, Oxford OX2 8DR, United Kingdom. > > This e-mail has been scanned for all viruses by Star. The service is > powered by MessageLabs. ______________________________ > __________________________________________ > _______________________________________________ > [email protected] > http://x-query.com/mailman/listinfo/talk >
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