On 8/24/07, Kirk Wythers <[EMAIL PROTECTED]> wrote:
snip
> This is part of what was confusing me. I didn't see %totals declared
> anywhere is the suggestion.
snip
Yeah, you can only tell it is a hash because of how it is used. I
believe the person who posted the example expected you to know what a
hash was and how to declare it.
snip
> Then, should I be declaring my%totals right up top and treating the
> variables like this?
>
> #! /usr/bin/perl -w
>
> use strict;
> use warnings;
>
> $, = ' '; # set output field separator
> $\ = "\n"; # set output record separator
>
> my%totals;
>
> my ( $year, $month, $doy, $tmax, $tmin, $par, $precip, $NH4, $NO3,
> $O3, $CO2, $V1, $V2, $V3, $V4 ) = split;
> # store totals by month as:
>
> $totals{$year}{$month}{doy} += $doy;
> $totals{$year}{$month}{tmax} += $tmax;
> $totals{$year}{$month}{tmin} += $tmin;
> $totals{$year}{$month}{par} += $par;
> $totals{$year}{$month}{precip} += $precip;
> etc....
>
> # store the count
> $totals{$year}{$month}{count} ++;
>
> print $year, $totals{$year}{$month}{doy} / $totals{$year}{$month}
> {count}, $totals{$year}{$month}{tmax} / $totals{$year}{$month}
> {count}, $totals{$year}{$month}{tmin} / $totals{$year}{$month}{count,
> etc....
snip
Yes, assuming that the += code is inside a loop that reads lines from
a file. Also, I am incredibly lazy and the thought of typing all of
that code gives me the shivers, so I would say
#!/usr/bin/perl
use strict;
use warnings;
my @sum = qw<tmax tmin par precip NH4 NO3 O3 CO2 V1 V2 V3 V4>;
my %totals;
while (<>) {
chomp;
my %rec;
my ($y, $m, $doy);
#put year, month, and doy in $y, $m, and $doy and the rest in %rec
($y, $m, $doy, @[EMAIL PROTECTED]) = split;
$totals{$y}{$m}{$_} += $rec{$_} for @sum;
$totals{$y}{$m}{count}++;
}
for my $y (sort keys %totals) {
for my $m (sort keys %{$totals{$y}}) {
my $rec = $totals{$y}{$m};
my @avg = map { $rec->{$_}/$rec->{count} } @sum;
print join("\t", $y, $m, @avg), "\n";
}
}
If I decided later that some columns should be summed and others
averaged then I could change it to
#!/usr/bin/perl
use strict;
use warnings;
#fields to sum
my @sum = qw<tmax tmin par precip NH4 NO3 O3 CO2 V1 V2 V3 V4>;
#fields to average
my @avg = qw<tmax tmin par NH4 NO3 O3 CO2 V1 V2 V3 V4>;
my %totals;
while (<>) {
chomp;
my %rec;
my ($y, $m, $doy);
#put year, month, and doy in $y, $m, and $doy and the rest in %rec
($y, $m, $doy, @[EMAIL PROTECTED]) = split;
$totals{$y}{$m}{$_} += $rec{$_} for @sum;
$totals{$y}{$m}{count}++;
}
for my $y (sort keys %totals) {
for my $m (sort keys %{$totals{$y}}) {
my %rec;
#make a copy of the data so totals can be used for other things
@[EMAIL PROTECTED], 'count'} = @[EMAIL PROTECTED],'count'};
#average only the fields in @avg
@[EMAIL PROTECTED] = map { $rec{$_}/$rec{count} } @avg;
print join("\t", $y, $m, @[EMAIL PROTECTED]), "\n";
}
}
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