foreach my $dataset (1..50) {
    my $data = myread( "$filename.$dataset" );
    $data = shiftfunction( $data, $shiftvalue );
    $data = normalize( $data, { normconstant => 1 } );
    mywrite( $data, "$newfilename.$dataset" );
}

##</code><code>##

for $i in 1-50 {
    $data = read "datafile.$i";
    shift $data 0.05;
    normalize $data constant=1.0;
    write $data "outfile.$i";
}