How can I sum data over five minute time intervals in Perl? - perl

Question

I have a file in below format.
DATE Time, v1,v2,v3
05:33:25,n1,n2,n3
05:34:25,n4,n5,n5
05:35:24,n6,n7,n8
and so on upto 05:42:25.
I want calculate the values v1, v2 and v3 for every 5 min interval. I have written the below sample code.
while (<STDIN>) {
my ($dateTime, $v1, $v2, $v3) = split /,/, $_;
my ($date, $time) = split / /, $dateTime;
}
I can read all the values but need help to sum all the values for every 5 min interval. Can anyone please suggest me the code to add the time and values for every 5 min.
Required output
05:33 v1(sum 05:33 to 05:37) v2(sum 05:33 to 05:33) v3(sum 05:33 to 05:33)
05:38 v1(sum 05:38 to 05:42) v2(sum 05:38 to 05:42) v3(sum 05:38 to 05:42)
and so on..

Answer 1

The code is a variation the previous answer by Sinan Ünür below, except:
(1) Function timelocal will allow you to read in Day,Month,Year -- so you can sum any five minute gap.
(2) Should deal with case where final time gap is < 5 minutes.
#!/usr/bin/perl -w
use strict;
use warnings;
use Time::Local;
use POSIX qw(strftime);
my ( $start_time, $end_time, $current_time );
my ( $totV1, $totV2, $totV3 ); #totals in time bands
while (<DATA>) {
my ( $hour, $min, $sec, $v1, $v2, $v3 ) =
( $_ =~ /(\d+)\:(\d+)\:(\d+)\,(\d+),(\d+),(\d+)/ );
#convert time to epoch seconds
$current_time =
timelocal( $sec, $min, $hour, (localtime)[ 3, 4, 5 ] ); #sec,min,hr
if ( !$end_time ) {
$start_time = $current_time;
$end_time = $start_time + 5 * 60; #plus 5 min
}
if ( $current_time <= $end_time ) {
$totV1 += $v1;
$totV2 += $v2;
$totV3 += $v3;
}
else {
print strftime( "%H:%M:%S", localtime($start_time) ),
" $totV1,$totV2,$totV3\n";
$start_time = $current_time;
$end_time = $start_time + 5 * 60; #plus 5 min
( $totV1, $totV2, $totV3 ) = ( $v1, $v2, $v3 );
}
}
#Print results of final loop (if required)
if ( $current_time <= $end_time ) {
print strftime( "%H:%M:%S", localtime($start_time) ),
" $totV1,$totV2,$totV3\n";
}
__DATA__
05:33:25,29,74,96
05:34:25,41,69,95
05:35:25,24,38,55
05:36:25,96,63,70
05:37:25,84,65,74
05:38:25,78,58,93
05:39:25,51,38,19
05:40:25,86,40,64
05:41:25,80,68,65
05:42:25,4,93,81
Output:
05:33:25 352,367,483
05:39:25 221,239,229

Answer 2

Obviously, not tested much, for lack of sample data. For parsing the CSV, use either Text::CSV_XS or Text::xSV rather than the naive split below.
Note:
This code does not make sure the output has all consecutive five minute blocks if the input data has gaps.
You will have problems if there are time stamps from multiple days. In fact, if the time stamps are not in 24-hour format, you will have problems even if the data are from a single day.
With those caveats, it should still give you a starting point.
#!/usr/bin/perl
use strict;
use warnings;
my $split_re = qr/ ?, ?/;
my #header = split $split_re, scalar <DATA>;
my #data;
my $time_block = 0;
while ( my $data = <DATA> ) {
last unless $data =~ /\S/;
chomp $data;
my ($ts, #vals) = split $split_re, $data;
my ($hr, $min, $sec) = split /:/, $ts;
my $secs = 3600*$hr + 60*$min + $sec;
if ( $secs > $time_block + 300 ) {
$time_block = $secs;
push #data, [ $time_block ];
}
for my $i (1 .. #vals) {
$data[-1]->[$i] += $vals[$i - 1];
}
}
print join(', ', #header);
for my $row ( #data ) {
my $ts = shift #$row;
print join(', ',
sprintf('%02d:%02d', (localtime($ts))[2,1])
, #$row
), "\n";
}
__DATA__
DATE Time, v1,v2,v3
05:33:25,1,3,5
05:34:25,2,4,6
05:35:24,7,8,9
05:55:24,7,8,9
05:57:24,7,8,9
Output:
DATE Time, v1, v2, v3
05:33, 10, 15, 20
05:55, 14, 16, 18

Answer 3

This is a good problem for Perl to solve. The hardest part is taking the value from the datetime field and identifying which 5 minute bucket it belongs to. The rest is just hashes.
my (%v1,%v2,%v3);
while (<STDIN>) {
my ($datetime,$v1,$v2,$v3) = split /,/, $_;
my ($date,$time) = split / /, $datetime;
my $bucket = &get_bucket_for($time);
$v1{$bucket} += $v1;
$v2{$bucket} += $v2;
$v3{$bucket} += $v3;
}
foreach my $bucket (sort keys %v1) {
print "$bucket $v1{$bucket} $v2{$bucket} $v3{$bucket}\n";
}
Here's one way you could implement &get_bucket_for:
my $first_hhmm;
sub get_bucket_for {
my ($time) = #_;
my ($hh,$mm) = split /:/, $time; # looks like seconds are not important
# buckets are five minutes apart, but not necessarily at multiples of 5 min
# (i.e., buckets could go 05:33,05:38,... instead of 05:30,05:35,...)
# Use the value from the first time this function is called to decide
# what the starting point of the buckets is.
if (!defined $first_hhmm) {
$first_hhmm = $hh * 60 + $mm;
}
my $bucket_index = int(($hh * 60 + $mm - $first_hhmm) / 5);
my $bucket_start = $first_hhmm + 5 * $bucket_index;
return sprintf "%02d:%02d", $bucket_start / 60, $bucket_start % 60;
}

Answer 4

I'm not sure why you would use the times starting from the first time, instead of round 5 minute intervals (00 - 05, 05 - 10, etc), but this is a quick and dirty way to do it your way:
my %output;
my $last_min = -10; # -10 + 5 is less than any positive int.
while (<STDIN>) {
my ($dt, $v1, $v2, $v3) = split(/,/, $_);
my ($h, $m, $s) = split(/:/, $dt);
my $ts = $m + ($h * 60);
if (($last_min + 5) < $ts) {
$last_min = $ts;
}
$output{$last_min}{1} += $v1;
$output{$last_min}{2} += $v2;
$output{$last_min}{3} += $v3;
}
foreach my $ts (sort {$a <=> $b} keys %output) {
my $hour = int($ts / 60);
my $minute = $ts % 60;
printf("%01d:%02d v1(%i) v2(%i) v3(%i)\n", (
$hour,
$minute,
$output{$ts}{1},
$output{$ts}{2},
$output{$ts}{3},
));
}
Not sure why you would do it this way, but there you go in procedural Perl, as example. If you need more on the printf formatting, go here.