Re: Calculating cumulative values

Thanks, Dimitre.

Two questions -

a) Will this work with .Net 2.0?

No, the two XSLT processors that come as part of  .NET 2.0 (the
classes XslTransform and XslCompiledTransform) only support XSLT 1.0.

However, in a .NET environment one can use Saxon.NET, which is a port
of Saxon 8.x and implements XSLT 2.0.

b) What are the external files : func-scanlDVC.xsl and func-Operators.xsl?

One can learn more about FXSL from the presentations made at the
Extreme Markup Languages Conference in Montreal 2006 (FXSL 2 -- for
XSLT 2.0, and FXSL 1 -- for XSLT 1.0) here:

Other papers about different important features of FXSL can be found
at the home page of FXSL:

--
Cheers,
Dimitre Novatchev
---------------------------------------
Truly great madness cannot be achieved without significant intelligence.
---------------------------------------
To invent, you need a good imagination and a pile of junk
-------------------------------------
You've achieved success in your field when you don't know whether what
you're doing is work or play

Simon

-----Original Message-----
From: Dimitre Novatchev [mailto:dnovatchev@xxxxxxxxx]
Sent: February 3, 2007 2:50 PM
To: xsl-list@xxxxxxxxxxxxxxxxxxxxxx
Subject: Re:  Calculating cumulative values

On 2/3/07, Andrew Welch <andrew.j.welch@xxxxxxxxx> wrote:

>
> You can just use XPath here, no need for recursion:
>
> <xsl:template match="point">
>  <xsl:copy>
>   <xsl:copy-of select="@*"/>
>   <xsl:attribute name="y2">
>     <xsl:value-of select="sum(./@y1|preceding-sibling::point[@x =
> current()/@x]/@y1)"/>
>   </xsl:attribute>
>  </xsl:copy>
> </xsl:template>

However evaluating this XPath expression repeatedly is O(N^2) and will
probably be slow for long lists.

Here is a solution, using the FXSL function

f:scanl1()

This transformation:

<xsl:stylesheet version="2.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
 xmlns:f="http://fxsl.sf.net/"
 exclude-result-prefixes="f"
>
 <xsl:import href="../f/func-scanlDVC.xsl"/>
 <xsl:import href="../f/func-Operators.xsl"/>

 <!-- To be applied on testFunc-scanlDVC3.xml -->
 <xsl:output omit-xml-declaration="yes" indent="yes"/>

 <xsl:template match="node()|@*">
   <xsl:copy>
     <xsl:apply-templates select="node()|@*"/>
   </xsl:copy>
 </xsl:template>

 <xsl:template match="set">
   <xsl:copy>
     <xsl:copy-of select="@*"/>
     <xsl:for-each-group select="point" group-by="@x">
        <xsl:for-each select="f:scanl1(f:add(), current-group()/@y1)">
           <point x="{current-group()[1]/@x}" y="{.}"/>
        </xsl:for-each>
    </xsl:for-each-group>
   </xsl:copy>
 </xsl:template>
</xsl:stylesheet>

When applied against the originally provided xml document:

<root id="theroot">
       <set id="1">
               <point x="1" y1="2" />
               <point x="1" y1="3" />
               <point x="1" y1="0" />
               <point x="1" y1="2" />
               <point x="1" y1="2" />
               <point x="2" y1="3" />
               <point x="2" y1="0" />
               <point x="2" y1="2" />
               <point x="3" y1="2" />
               <point x="3" y1="3" />
               <point x="3" y1="1" />
               <point x="3" y1="2" />
               <point x="3" y1="2" />
       </set>
       <set id="2">
               <point x="1" y1="2" />
               <point x="1" y1="3" />
               <point x="1" y1="0" />
               <point x="1" y1="2" />
               <point x="2" y1="2" />
               <point x="3" y1="2" />
               <point x="3" y1="2" />
               <point x="3" y1="2" />
       </set>
       <set id="n">
               <point x="1" y1="2" />
               <point x="1" y1="3" />
               <point x="1" y1="2" />
               <point x="2" y1="3" />
               <point x="2" y1="0" />
               <point x="2" y1="2" />
               <point x="3" y1="3" />
       </set>
</root>

produces the wanted result:

<root id="theroot">
  <set id="1">
     <point x="1" y="2"/>
     <point x="1" y="5"/>
     <point x="1" y="5"/>
     <point x="1" y="7"/>
     <point x="1" y="9"/>
     <point x="2" y="3"/>
     <point x="2" y="3"/>
     <point x="2" y="5"/>
     <point x="3" y="2"/>
     <point x="3" y="5"/>
     <point x="3" y="6"/>
     <point x="3" y="8"/>
     <point x="3" y="10"/>
  </set>
  <set id="2">
     <point x="1" y="2"/>
     <point x="1" y="5"/>
     <point x="1" y="5"/>
     <point x="1" y="7"/>
     <point x="2" y="2"/>
     <point x="3" y="2"/>
     <point x="3" y="4"/>
     <point x="3" y="6"/>
  </set>
  <set id="n">
     <point x="1" y="2"/>
     <point x="1" y="5"/>
     <point x="1" y="7"/>
     <point x="2" y="3"/>
     <point x="2" y="3"/>
     <point x="2" y="5"/>
     <point x="3" y="3"/>
  </set>
</root>

--
Cheers,
Dimitre Novatchev
---------------------------------------
Truly great madness cannot be achieved without significant intelligence.
---------------------------------------
To invent, you need a good imagination and a pile of junk
-------------------------------------
You've achieved success in your field when you don't know whether what
you're doing is work or play