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lib/AI/FuzzyEngine.pm  view on Meta::CPAN

    # Get size of wrapping piddle (using a trick)
    # applying valid expansion rules for element wise operations
    my $zeros = PDL->pdl(0);
    #        v-- does not work due to threading mechanisms :-((
    # $zeros += $_ for @pdls;
    # Avoid threading!
    for my $p (@pdls) {
        croak "Empty piddles are not allowed" if $p->isempty();
        eval { $zeros = $zeros + $p->zeros(); 1
            } or croak q{Can't expand piddles to same size};
    }

    # Now, cat 'em by expanding them on the fly
    my $vals = PDL::cat( map {$_ + $zeros} @pdls );
    return $vals;
};

1;

=pod

=head1 NAME

lib/AI/FuzzyEngine.pm  view on Meta::CPAN

    # Input data is a pdl of arbitrary dimension
    my $data = pdl( [0, 4, 6, 10] );
    $severity->fuzzify( $data );

    # Membership degrees are piddles now:
    print 'Severity is high: ', $severity->high, "\n";
    # [0 0.5 1 1]

    # Other variables might be piddles of other dimensions,
    # but all variables must be expandible to a common 'wrapping' piddle
    # ( in this case a 4x2 matrix with 4 colums and 2 rows)
    my $level = pdl( [0.6],
                     [0.2],
                   );
    $threshold->fuzzify( $level );

    print 'Threshold is low: ', $threshold->low(), "\n";
    # [
    #  [0.33333333]
    #  [         1]

lib/AI/FuzzyEngine.pm  view on Meta::CPAN

    $var_b->fuzzify( pdl([1, 2], [3, 4]) );

Defuzzification returns a piddle if any of the membership
degrees of the function's sets is a piddle:

    my $val = $var_a->defuzzify(); # $var_a returns a 1dim piddle with two elements

So do the fuzzy operations as provided by the fuzzy engine C<$fe> itself.

Any operation on more then one piddle expands those to common
dimensions, if possible, or throws a PDL error otherwise. 

The way expansion is done is best explained by code
(see C<< AI::FuzzyEngine->_cat_array_of_piddles(@pdls) >>).
Assuming all piddles are in C<@pdls>,
calculation goes as follows:

    # Get the common dimensions
    my $zeros = PDL->pdl(0);
    # Note: $zeros += $_->zeros() for @pdls does not work here