dataset 1:
vr 1 2 3 5 
o1 a a b b 
o2 c c d d 
o3 e e f f 

dataset 2:
id date1 age 
1  2005  30  
2  2006  25 
3  2005  22
4  2004  23  
5  2006  25  

merged/tranposed dataset:
id date1 age o1 o2 o3
1  2005  30  a  c  e
2  2006  25  a  c  e
3  2004  22  b  d  f
4  2004  23  
5  2006  25  b  d  f 

##</code><code>##

$ids = `head -1 dataset1`;  
@matchid = split(" ", $ids);
shift(@matchid);

open(IN, "dataset2" ) || die 
open(OUT, ">mergeddataset") || die ;

$line=<IN>; chomp $line;
$h = `cut -f1 dataset1`;
@header = split(/\n/,$h);
shift(@header);
print OUT  $line." ".join(" ",@header)."\n";

while ($line=<IN>)
{
chomp $line;
@match=split(" ",$line);
foreach $id (@header)
	{
          if ($id eq $match[1])
          {
          $column=`head -1 dataset1|tr -s "\t" "\n" | grep -n $id|cut -f1 -d":"`;
	  chomp $column;
	  $a = `cut -f$column dataset1| tail +2 | tr -s '\n' ' '`;
          chomp $a;
	  @b = split(/ +/, $a);
          print OUT $line." ".join(" ",@b)."\n";
          }
        }
}

close(OUT);
close(IN);