Re^3: manipulating a data table

[kevbot]

I was tempted to go for a Fortran web service with SQL (http://fortran.io), but I settled for a solution using Data::Table.

#!/usr/bin/env perl

use strict;
use warnings;

use Data::Table;

# Giving '0' as the second arg to Data::Table::fromTSV,
# results in a Data::Table with column names of col1, col2 and col3

my $t = Data::Table::fromTSV("data.tsv", 0);
my $nrow = $t->nofRow;
my @row_numbers = 1..$nrow;

# Sort by 'col2' as numeric values in decending order
$t->sort( 'col2', 0, 1 );

# Add a new column that contains the row indices for the 'col2' sort o
+rder
$t->addCol( \@row_numbers, 'col2order' );

# Sort by 'col3' as numeric values in decending order
$t->sort( 'col3', 0, 1 );

# Add a new column that contains the row indices for the 'col3' sort o
+rder
$t->addCol( \@row_numbers, 'col3order' );

# Sort by 'col1' as string values in ascending order
$t->sort( 'col1', 1, 0 );

# Get a subtable with the columns of interest
my $result = $t->subTable( undef, [ 'col1', 'col2order', 'col3order' ]
+ );

print $result->tsv;

exit;

This input is in data.tsv:

a    23    11
b    24    15
c    16    19
d    8    2
e    40    41

The output is:

col1    col2order    col3order
a    3    4
b    2    3
c    4    2
d    5    5
e    1    1