in reply to Re: Keeping Unique Elements in Array!
in thread Keeping Unique Elements in Array!

You are mentioning that if this is added to the array:
            [
            'ALICE WONDER',
            '9876543',
            '2009',
            '15.00',
            '711',
            '4',
            '5',
            '9'
            ],

[download]

another loop has to be added to the code? What if you dont know the number of elements in this array?

Replies are listed 'Best First'.
Re^3: Keeping Unique Elements in Array!
by almut (Canon) on May 01, 2009 at 18:46 UTC

    What I meant is something like this, in which case you can have any number of arrays with any number of rows: 

    my $all_val = [];
for my $aref (@$array_ref_x) {
    my $i = 0;
    for my $row (@$aref) {
        $all_val->[$i] = '' unless defined $all_val->[$i];  # for 'use
+ warnings'
        $all_val->[$i] = $row if $row gt $all_val->[$i];
        $i++;
    }
}

    [download]
[reply]
[d/l]
      That's a great answer, one more question since you mentioned numeric values and of course use > for numeric ones, is there a way in Perl to detect and do the evaluation on both cases, if it is numeric or not on the same array like the sample code above?
[reply]

        There are several ways, for example Scalar::Util has looks_like_number(), or Regexp::Common's $RE{num}{real}.  Alternatively, in your specific case, you might just see if treating it as a number evaluates to zero, and then do a string comparison... (the latter wouldn't work if you also have negative numbers, though)

[reply]
[d/l]
[select]
        Is this acceptable?
        my $all_val = [];
for my $aref (@$array_ref_x) {
    my $i = 0;
    for my $row (@$aref) {
    
        $all_val->[$i] = '' unless defined $all_val->[$i];  # for use 
+strict
        # Check if numeric
        if ($all_val->[$i] =~ /^-?\d/){
        $all_val->[$i] = $row if $row > $all_val->[$i];
        }else{
        $all_val->[$i] = $row if $row gt $all_val->[$i];
        }
        
        $i++;

    }

}




print Dumper $all_val;

        [download]
[reply]
[d/l]
      It does not scale like I thought, I was think that it could analize it by lets say the first and second elements and do the rest, here is a sample of what I am sying:
      my $array_ref_x = [

            [
            'ALICE WONDER',
            '9876543',
            '2009',
            '11.00',
            '711',
            '20',
            '0',
            '8',
            ],
          
            [
            'ALICE WONDER',
            '9876543',
            '2009',
            '11.00',
            '711',
            '3',
            '2',
            '0',
            ],

            [
            'ALICE WONDER',
            '9876543',
            '2009',
            '15.00',
            '711',
            '4',
            '5',
            '11',
            ],

            [
            'ALICE WONDER',
            '9876543',
            '2008',
            '15.00',
            '717',
            '4',
            '5',
            '9',
            ],
            
            [
            'John Day',
            '456789',
            '2011',
            '50.00',
            '717',
            '4',
            '22',
            '9',
            ],
            
            [
            'John Day',
            '456789',
            '2011',
            '50.00',
            '817',
            '4',
            '5',
            '90',
            ],

            [
            'Mary Ann',
            '123988',
            '2002',
            '10.00',
            '119',
            '5',
            '3',
            '0',
            ],
          
];

#Results
my $array_ref_x = [

[
          'ALICE WONDER',
          9876543,
          2009,
          '15.00',
          717,
          20,
          5,
          11
        ],
    [
                'John Day',
                '456789',
                '2011',
                '50.00',
                '817',
                '4',
                '22',
                '90',
                ],

             [
            'Mary Ann',
            '123988',
            '2002',
            '10.00',
            '119',
            '5',
            '3',
            '0',
            ],         
];

      [download]
[reply]
[d/l]

        Ah, I see why you were thinking of uniqueness... Maybe something like this, combining the idea of max() and uniqueness via hash: 

        ...
# group arrays by person+id
my %persons;
for my $aref (@$array_ref_x) {
    my $uniq_key = "$aref->[0] $aref->[1]";
    push @{$persons{$uniq_key}}, $aref;
}
    
my $all_val = [];
for my $aref_person (values %persons) {
    push @$all_val, my $tmp = [];
    for my $aref (@$aref_person) {
        @$tmp[0..1] = @$aref[0..1];
        for my $i (2..$#$aref) {
            $tmp->[$i] = 0 unless defined $tmp->[$i];
            $tmp->[$i] = $aref->[$i] if $aref->[$i] > $tmp->[$i];
        }
    }
}

print Dumper $all_val;

__END__
$VAR1 = [
          [
            'John Day',
            '456789',
            2011,
            '50.00',
            817,
            4,
            22,
            90
          ],
          [
            'ALICE WONDER',
            '9876543',
            2009,
            '15.00',
            717,
            20,
            5,
            11
          ],
          [
            'Mary Ann',
            '123988',
            2002,
            '10.00',
            119,
            5,
            3,
            0
          ]
        ];

        [download]
[reply]
[d/l]

In Section Seekers of Perl Wisdom