#!/usr/bin/perl -w
use strict;

my %dataset;

while (<>) {
   # $_ => Id, Loc, Value, Etime

   my ($id, $loc, $value, $etime) = split(/,\s+/, $_);

   $dataset{$id}{$etime} = { "Value" => $value,
                             "Loc" => $loc,
                           };
}

foreach my $id (sort keys %dataset) {
   foreach my $etime ( sort { $dataset{$id}{$a}{Loc} cmp $dataset{$id}{$b}{Loc} } keys %{$dataset{$id}}) {
      my $loc = $dataset{$id}{$etime}{Loc};
      my $value = $dataset{$id}{$etime}{Value};

      printf(STDOUT "%2s, %6s, %.1f, %i\n", $id, $loc, $value, $etime);
   }
}