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

Hi, I need convert 'associated lists' into a matrices that is accumulative of integers. Please help! I have searched high and dry and could not find a solution. Its making my hair fall out this week.. 

id1    id2    int
208    10000    1
208    10000    7
207    10000    3
8517   1147    1
3551   1147    2

   id1\id2      1147     10000
       207         0         3
       208         0         8
      3551         1         0
      8517         1         2

[download]
RESOLVED RESOLVED RESOLVED 






20x20-NMS parsers # cat list2
d1    id2       int
HAT    KNIFE    1
HAT    KNIFE    7
BALL   KNIFE    3
CAT    CLOTH    1
DOG    CLOTH    2


20x20-NMS parsers # cat test2.list | perl test2.pl
$matrix{CAT}{CLOTH} = 1
$matrix{DOG}{CLOTH} = 2
$matrix{HAT}{KNIFE} = 8
$matrix{BALL}{KNIFE} = 3
Delete Ball
$matrix{CAT}{CLOTH} = 1
$matrix{DOG}{CLOTH} = 2
$matrix{HAT}{KNIFE} = 8
Match the letter "O"

DOG

yep, HAT is there!
Print Matrix
       CLOTH  KNIFE
CAT        1      0
DOG        2      0
HAT        0      8
Done!



my %matrix;
while (<>) {
    my ($id1, $id2, $int) = split;
    $matrix{$id1}{$id2} += $int;
}

foreach $key1 (keys %matrix) {
        foreach $key2 (keys %{%matrix->{$key1}}) {
                print "\$matrix{$key1}{$key2} = $matrix{$key1}{$key2} 
+";
                }
        print"\n";
        }

# delete key
print "Delete Ball\n"; delete ($matrix{"BALL"});


foreach $key1 (keys %matrix) {
        foreach $key2 (keys %{%matrix->{$key1}}) {
           print "\$matrix{$key1}{$key2} = $matrix{$key1}{$key2} ";
           }
        print"\n";
        }

# Match
print "Match the letter \"O\"\n";
foreach $key1 (keys %matrix) {
        foreach $key2 (keys %{%matrix->{$key1}}) {
                @match = grep (/O/i, $key1);
                print "@match";
                }
        print"\n";
        }

# check for key existence
 if (exists($matrix{"HAT"}))
        {
        print "yep, HAT is there!\n";
        }

# Print Matrix
print "Print Matrix\n";
my @down = keys %matrix;
my @across = do {my %s; grep {!$s{$_}++} map {keys %$_} values %matrix
+};

my $l = 0;
$l < length ($_) and $l = length $_ for @down, @across;

print " " x $l;
printf "  %-${l}s", $_ for @across;
print "\n";
foreach my $d (@down) {
    printf "%-${l}s", $d;
    printf "  %${l}d", $matrix{$d}{$_} || 0 for @across;
    print "\n";
}

print"Done!\n";

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Replies are listed 'Best First'.
Re: Associated lists to matrices - and accumalted integers
by JavaFan (Canon) on Nov 06, 2009 at 14:43 UTC
    You probably want hashes instead of arrays. Here's how I would do it, assuming three integers per line: 
    my %data;
while (<>) {
    my ($id1, $id2, $int) = split;
    $data{$id1}{$id2} = $int;
}

    [download]
[reply]
[d/l]
      Hi, thanks. Sorry, from that I still dont get how I can parse a file like this.. 
      
id1    id2    int
HAT    KNIFE    1
HAT    KNIFE    7
BALL   KNIFE    3
CAT    CLOTH    1
DOG    CLOTH    2

      [download]
      To produce a table like this (notice KNIFE and HAT total is 8). Its 2am here, and would love to get this down else my wife is going to kill be if Im stuck on this all weekend. So your help much appreciated, first time I have asked for help like this. 
      
             CLOTH     KNIFE
   BALL        0         3
   HAT         0         8
   DOG         1         0
   CAT         1         2

      [download]
[reply]
[d/l]
[select]
        Change the second = in my code to +=.
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[d/l]
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