timeseries/top_n

86 lines
2.3 KiB
Perl
Executable File

#!/usr/bin/perl -w
use strict;
=head1 NAME
top_n - get top n (of many) time series
=head1 SYNOPSIS
top_n n f v
This script expects a file in tab-separated format containing all series mixed together in
"normalized" or "vertical" format,
e.g.,
2006-07-22T20:00:00 Wien/Innere Stadt 31.5
2006-07-22T20:00:00 Wien/Hohe Warte 29.5
2006-07-22T21:00:00 Wien/Innere Stadt 30.9
2006-07-22T21:00:00 Wien/Hohe Warte 27.9
2006-07-22T22:00:00 Wien/Innere Stadt 30.1
2006-07-22T22:00:00 Wien/Hohe Warte 26.2
...
n is the number of time series to extract.
f is the number of the column with the series names, starting at 0. In the example above, this would be 1.
v is the number of the column with values to be used for sorting. In the example above, this would be 2
(there is only one column with values in this example).
All values for a given series are added, and the the n series with the highest sum are selected.
Finally all records from the selected series and an additional series "OTHER" representing the sum
of all other series are printed.
=cut
my $n = shift;
my $f = shift;
my $v = shift;
my @data;
my %s;
while (<>) {
chomp;
my @a = split(/\t/);
push @data, [@a];
$s{$a[$f]} += $a[$v];
}
my @top_n = (sort { $s{$b} <=> $s{$a} } keys %s )[ 0 .. $n - 1 ];
my %top_n = map { $_ => 1 } @top_n;
my %index;
for my $i (0 .. $#data) {
unless ($top_n{$data[$i][$f]}) {
# this is a bit tricky, as records for the same point in time for
# different series can be scattered all over the place. We assume
# that all columns except $f and $v are relevant to the point in
# time (or some other distinguishing criterium), so we save the value,
# set $v and $f to fixed values and concatenate all columns.
# This will get a unique value iff all columns except $f and $v are unique.
# If we have seen this value before, we add the current value to
# the record with this value and undef the current value. Otherwise we
# record the index of the current record.
my $val = $data[$i][$v];
$data[$i][$v] = 0;
$data[$i][$f] = 'OTHER';
my $k = join("\t", @{$data[$i]});
if (defined($index{$k})) {
$data[$index{$k}][$v] += $val;
$data[$i][$v] = undef;
} else {
$data[$i][$v] = $val;
$index{$k} = $i;
}
}
}
for (@data) {
if (defined($_->[$v])) {
print join("\t", @$_), "\n";
}
}