A week ago a posted the following problem and Abel Braaksma was kind enough to
to give it some consideration.

I have in the meantime come up with a solution and would like to
solicit your comments
on how to make it more simple and clear. There is a real question here
as well: Where
does the space in front of the closing bracket come from and how do I
get rid of it?

Here is my solution (I omitted the header line) and I appended my
original problem:

--- begin example.xsl ---
<?xml version="1.0" encoding="UTF-8"?>
<?altova_samplexml C:\workspaces\tmp\xsl\example.xml?>
<xsl:stylesheet version="2.0"
               xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
               xmlns:fn="http://www.w3.org/2005/xpath-functions"
               xmlns:xs="http://www.w3.org/2001/XMLSchema">

   <xsl:variable name="delimiter" select="'; '" />
   <xsl:variable name="newline" select="'&#10;'" />

   <xsl:template match="/">
       <xsl:apply-templates/>
   </xsl:template>

       <xsl:variable name="this" select="." />
       <xsl:variable name="dates" select="distinct-values(date/@value)" />

       <xsl:variable name="max-count" >
           <xsl:value-of select="max(for $date in $dates return
count(date[@value = $date]))" />
       </xsl:variable>

       <xsl:for-each select="(1 to $max-count)" >
           <xsl:variable name="i" select="." />
           <xsl:value-of select="$this/@value" />
           <xsl:value-of select="$delimiter" />
           <xsl:for-each-group select="$this/date" group-by="@value" >
               <xsl:if test="current-group()[$i]/@string" >
                   <xsl:value-of
select="concat(current-group()[$i]/@string, ' [',
current-group()[$i]/@count), ']'" />
               </xsl:if>
               <xsl:value-of select="$delimiter" />
           </xsl:for-each-group>

           <xsl:value-of select="$newline" />
       </xsl:for-each>
   </xsl:template>
</xsl:stylesheet>
--- end example.xsl ---

I have a list of date elements in my xml that I want to output in
columns in a csv file.
If the same date occurs more than once, I want another line in the
respective column
and the label in the first column.

I think I should group the dates and then cicle thru and output the
line with all 1st elements in the group, then all 2nd elements in the
second line etc.

--- begin example.xml ---
<?xml version="1.0" encoding="UTF-8"?>
<top>
  <logpoint value="AAA" >
      <date value="2007-01-01" count="1" string="aaa"/>
      <date value="2007-01-01" count="11" string="xxx"/>
      <date value="2007-01-02" count="2" string="bbb"/>
      <date value="2007-01-03" count="3" string="ccc"/>
      <date value="2007-01-03" count="4" string="ddd"/>
      <date value="2007-01-03" count="41" string="yyy"/>
      <date value="2007-01-04" count="5" string="eee"/>
  </logpoint>
  <logpoint value="BBB" >
      <date value="2007-01-01" count="31" string="lll"/>
      <date value="2007-01-02" count="32" string="mmm"/>
      <date value="2007-01-03" count="33" string="nnn"/>
      <date value="2007-01-04" count="34" string="ooo"/>
  </logpoint>
</top>
--- begin example.xml ---

desired output:
--- begin example.csv ---
logpoint;2007-01-01;2007-01-02;2007-01-03;2007-01-04;
AAA;aaa[1];bbb[2];ccc[3];eee[5];
AAA;xxx[11];;ddd[4];;
AAA;;;yyy[41];;
BBB;lll[31];mmm[32];nnn[33];ooo[34];
--- end example.csv ---