#!C:/strawberry/perl/bin/perl.exe
#
# See http://rick.measham.id.au/pdf-api2/
#
use strict;
use warnings;
use Data::Dumper::Concise;

my @records;

while(my $record = <DATA>) {
    push(@records, [ split(/\s+/, $record) ]);
}

report({
    group_by    => 0,
    sum_columns => [ 2, 3 ],
    records     => \@records,
});

report({
    group_by    => 1,
    sum_columns => [ 2, 3 ],
    records     => \@records,
});

report({
    group_by    => 2,
    sum_columns => [ 3 ],
    records     => \@records,
});

exit(0);


sub report {
    my ($args) = @_;


    # sum columns by group
    my %groups;
    foreach my $record (@{$args->{records}}) {
        my $group = $groups{$record->[$args->{group_by}]} //= {};

        $group->{count}++;

        foreach my $sum_column (@{$args->{sum_columns}}) {
            $group->{sum}->{$sum_column} += $record->[$sum_column];
        }
    }

    # produce output
    print "example output: group by column $args->{group_by}, sum columns " .
        join(', ', @{$args->{sum_columns}}) . "\n";
    foreach my $group (sort keys %groups) {
        print join(' ',
            $group,
            map {
                (
                    $groups{$group}->{count},
                    $groups{$group}->{sum}->{$_}
                )
            } @{$args->{sum_columns}}
        ) . "\n";;
    }

    print "\n";
}




__DATA__
U1     ID1     100     280
U1     ID1     137     250
U2     ID2     150     375
U1     ID2     100     100
U3     ID1     100     600
U9     ID3     137     200

##</code><code>##

example output: group by column 0, sum columns 2, 3
U1 3 337 3 630
U2 1 150 1 375
U3 1 100 1 600
U9 1 137 1 200

example output: group by column 1, sum columns 2, 3
ID1 3 337 3 1130
ID2 2 250 2 475
ID3 1 137 1 200

example output: group by column 2, sum columns 3
100 3 980
137 2 450
150 1 375