(:
   file:    dt08_189_final.xq
   date:    07-Aug-2009
   author:  Gary Lewis
   purpose: Merges the XML with enrollment, unemployment rate, and recession data for the project addressing the question:
            Is higher education countercyclical?

            1. Documentation is available at: http://garymlewis.com/instchg/public/xquery/dt08_189_doc.xq.
               Follow the steps in this documentation to Step 13.
            2. Run the current program as follows (Step 13 in documentation):
               zorba -o dt08_189_final.xml -f -q dt08_189_final.xq -z indent=yes

:)

<time_series>
{
let $tmp1 :=
   for $year in doc("dt08_189_enrl.xml")/tabn189/year/@value
   let $enrl := doc("dt08_189_enrl.xml")/tabn189/year[@value = $year]/enrl,                     (: flatten out data structure :)
       $enrl_date := concat($year,'-','10-01'),
       $c2 := $enrl[@column = 2]/@pctchg,
       $c3 := $enrl[@column = 3]/@pctchg,
       $c4 := $enrl[@column = 4]/@pctchg,
       $c5 := $enrl[@column = 5]/@pctchg,
       $c6 := $enrl[@column = 6]/@pctchg,
       $c7 := $enrl[@column = 7]/@pctchg,
       $c8 := $enrl[@column = 8]/@pctchg,
       $c9 := $enrl[@column = 9]/@pctchg,
       $c10 := $enrl[@column = 10]/@pctchg,
       $c11 := $enrl[@column = 11]/@pctchg,
       $c12 := $enrl[@column = 12]/@pctchg,
       $c13 := $enrl[@column = 13]/@pctchg,
       $c14 := $enrl[@column = 14]/@pctchg,
       $c15 := $enrl[@column = 15]/@pctchg,
       $c16 := $enrl[@column = 16]/@pctchg
   return
      <series_date value="{$enrl_date}" c2="{$c2}" c3="{$c3}" c4="{$c4}" c5="{$c5}" c6="{$c6}" c7="{$c7}" c8="{$c8}" c9="{$c9}" c10="{$c10}" c11="{$c11}" c12="{$c12}" c13="{$c13}" c14="{$c14}" c15="{$c15}" c16="{$c16}" />
return
let $tmp2 :=
   for $j in doc("dt08_189_econ.xml")/time_series/series_date
   let $series_date := $j/@value,
       $k := $tmp1[@value = $series_date]
   return
      <series_date value="{$series_date}" unemployment_rate="{$j/@unemployment_rate}" recession_indicator="{$j/@recession_indicator}" pctchg_dt08_189_c2="{$k/@c2}" pctchg_dt08_189_c3="{$k/@c3}" pctchg_dt08_189_c4="{$k/@c4}" pctchg_dt08_189_c5="{$k/@c5}" pctchg_dt08_189_c6="{$k/@c6}" pctchg_dt08_189_c7="{$k/@c7}" pctchg_dt08_189_c8="{$k/@c8}" pctchg_dt08_189_c9="{$k/@c9}" pctchg_dt08_189_c10="{$k/@c10}" pctchg_dt08_189_c11="{$k/@c11}" pctchg_dt08_189_c12="{$k/@c12}" pctchg_dt08_189_c13="{$k/@c13}" pctchg_dt08_189_c14="{$k/@c14}" pctchg_dt08_189_c15="{$k/@c15}" pctchg_dt08_189_c16="{$k/@c16}" />
return $tmp2
}
</time_series>