Thanks for your XQuery 1-dimensional sample. There are 4 XQuery with JSONiq implemenations named on jsoniq.org: 28.io, Zorba, IBM Websphere DataPower Integration Appliance and Pascal XQuery engine
It seems not to be that easy to measure runtime. Since http://try.zorba.io allows to share and run code I used that. The method I found was to place Zorba's datetime:current-time() in result sequence as first and last elements. And the matrix multiplications need to be executed often to result in measurable times (I did use 10.000.000). These are JSONiq (1) and your XQuery (2) implemenations: http://try.zorba.io/queries/xquery/vq+kL9tWK+jmntDZz0oxDcyrypA= http://try.zorba.io/queries/xquery/NIlfOIBmkdvt8+2zNmvM8Hf1+bo= The times reported are quite different although run on same processor: PT1.713634S (JSONiq) versus PT9.77805S (XQuery) Yes, that is only result for one processor. But I would assume even (much) bigger differences in case the matrix dimensions become bigger and not toy like as in the examples. (1) import module namespace datetime = "http://www.zorba-xquery.com/modules/datetime";; declare variable $A := [ [1,2], [3,4], [5,6], [7,8] ]; declare variable $B := [ [1,2,3], [4,5,6] ]; declare variable $N := 10000000; let $R := ( datetime:current-time(), for $h in 1 to $N return [ for $i in 1 to count(jn:members($A)) return [ for $k in 1 to count(jn:members($B(1))) return fn:sum( for $j in 1 to count(jn:members($B)) return $A($i)($j) * $B($j)($k) ) ] ] , datetime:current-time() ) return $R[count($R)] - $R[1] (2) import module namespace datetime = "http://www.zorba-xquery.com/modules/datetime";; declare variable $a:=(2, (:2 columns :) 1,2, 3,4, 5,6, 7,8); declare variable $b:=(3, (:3 columns :) 1,2,3, 4,5,6); declare variable $N := 10000000; let $R := ( datetime:current-time(), for $h in 1 to $N return ( $b[1], for $i in 1 to xs:int((count($a) -1) div $a[1]), $j in 1 to xs:int($b[1]) return sum( for $k in 1 to xs:int($a[1]) return ($a[($i -1)*$a[1]+$k+1] * $b [($k -1)*$b[1]+$j+1]) ) ) , datetime:current-time() ) return $R[count($R)] - $R[1] Mit besten Gruessen / Best wishes, Hermann Stamm-Wilbrandt Level 3 support for XML Compiler team and Fixpack team lead WebSphere DataPower SOA Appliances https://www.ibm.com/developerworks/mydeveloperworks/blogs/HermannSW/ https://twitter.com/HermannSW/ http://stamm-wilbrandt.de/GraphvizFiddle/ ---------------------------------------------------------------------- IBM Deutschland Research & Development GmbH Vorsitzende des Aufsichtsrats: Martina Koederitz Geschaeftsfuehrung: Dirk Wittkopp Sitz der Gesellschaft: Boeblingen Registergericht: Amtsgericht Stuttgart, HRB 243294 From: David Carlisle <[email protected]> To: Hermann Stamm-Wilbrandt/Germany/IBM@IBMDE, [email protected], Date: 02/02/2014 01:44 AM Subject: Re: [xquery-talk] Matrix Multiplication (JSONiq) On 01/02/2014 23:33, Hermann Stamm-Wilbrandt wrote: > > Last Sylvester there was a thread on Matrix Multiplication in > XQuery > http://markmail.org/message/7q7qnbbnjo7cljzv?q=list:com.x-query.talk +matrix+multiplication > > > > The biggest problem identified was that XQuery does not allow for > efficient representation of 2+dimensional arrays. > well it does, but as in other languages that only really have 1-D arrays (or languages such as C or Fortran where 2D arrays are a thin veneer over 1D arrays), you need to store a 2 D array as a 1D array with an additional integer giving the stride or leading dimension (in row or column order). To keep the arrays self contained I stored this as the first item in each sequence in the example below. > JSON does provide 2+dimensional arrays for free. > > I did not measure performance yet, but this JSONiq script looks very > similar to what would be done in C: > http://try.zorba.io/queries/xquery/jFd3Q8f82HuZGzcYDzQpdN4SdfY= > > declare variable $A := [ [1,2], [3,4], [5,6], [7,8] ]; declare > variable $B := [ [1,2,3], [4,5,6] ]; > > [ for $i in 1 to count(jn:members($A)) return [ for $k in 1 to > count(jn:members($B(1))) return fn:sum( for $j in 1 to > count(jn:members($B)) return $A($i)($j) * $B($j)($k) ) ] ] > > In Xquery 1 you could do let $a:=(2, (:2 columns :) 1,2, 3,4, 5,6, 7,8), $b:=(3, (:3 columns :) 1,2,3, 4,5,6) return ( $b[1], for $i in 1 to xs:int((count($a) -1) div $a[1]), $j in 1 to xs:int($b[1]) return sum( for $k in 1 to xs:int($a[1]) return ($a[($i -1)*$a[1]+$k+1] * $b[($k -1)*$b[1]+$j+1]) ) ) which produces 3 (:3 columns :) 9 12 15 19 26 33 29 40 51 39 54 69 > And much simpler than in XSLT: > http://rosettacode.org/wiki/Matrix_multiplication#XSLT_1.0: > > As the above is in fact only Xpath 2, you could do the identical expression in XSLT 2 David _______________________________________________ [email protected] http://x-query.com/mailman/listinfo/talk
