Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question:

This isn't homework... But it might look that way. It's a project I'm working on for work.

This works OK but looks very inefficient... All the 'or' statements are mucking me up and I can't figure out a slicker way to do this. Take a look and see if you can do better (I'm sure at least some of you can). This is under use strict; and -w.

This code eats a text file and spits out values for each of the variables at one minute intervals, using UNIX time. The parsing is nice, this is the ugly bit - the output. 

# Figure out the first timestamp
foreach my $bar (sort keys %master) { $j = $bar; last; }
# Figure out the last timestamp
foreach my $bar (reverse sort keys %master) { $l = $bar; last; }

do { 
    my $out;
    $out .= "$j,";     
    $out .= $master{$j}{'CCMT'} || '0';
    $out .= ",";
    $out .= $master{$j}{'CCOA'} || '0';
    $out .= ",";
    $out .= $master{$j}{'CDEC'} || '0';
    $out .= ",";
    $out .= $master{$j}{'CFST'} || '0';
    $out .= ",";
    $out .= $master{$j}{'CREF'} || '0';
    $out .= ",";
    $out .= $master{$j}{'CRSP'} || '0';
    $out .= ",";
    $out .= $master{$j}{'CVEH'} || '0';
    $out .= "\n"; 
    print $out;
    $j += 60; 
   } while $j <= $l;

[download]

Replies are listed 'Best First'.
Re: Golf, Anyone? Stupid output questions
by VSarkiss (Monsignor) on Apr 17, 2002 at 02:38 UTC

    If you need them in a specific order: 

    my @keys = qw(CCMT CCOA CDEC CFST CREF CRSP CVEH);
do {
    print
       $j, ',',
       join(',', map { master{$j}{$_} || '0' } @keys),
       "\n";
    $j += 60;
} while $j <= $l;

    [download]
    One note: I think do while is a really icky construct, but I wanted to reproduce your code.

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Re: Golf, Anyone? Stupid output questions
by belg4mit (Prior) on Apr 17, 2002 at 02:34 UTC
    First off, why are you doing two sorts? Sorts are pretty damn expensive (or so I'm told). Especially in this case, I would imagine, since hash lookups on anagrams (act, atc, cat, cta, tat, tca) are particularly slow. Being timestamps they are restricted to a 10 character set, and most likely be all of the same length, thusly ensuring that a portion of a decent sized will be anagrams. 
    ($j, $l) = (sort keys %master)[0,-1];

    [download]
    Second 
    #Might go with a C-style for-loop here.
while($j <= $l){
 for my $elem (qw(CCMT ...)){
  $out .= "," . ($master{$j}{$elem} || '0');
 }
 $j+=60;
}

    [download]

    --
    perl -pe "s/\b;([mnst])/'\1/mg"

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Re: Golf, Anyone? Stupid output questions
by crazyinsomniac (Prior) on Apr 17, 2002 at 02:34 UTC
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