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lib/AI/NeuralNet/Hopfield.pm  view on Meta::CPAN

		my $transposed_column_matrix = &transpose($column_matrix);
		
		my $dot_product = &dot_product($input_matrix, $transposed_column_matrix);
		
		#say $dot_product;

		if ($dot_product > 0) {
			$output[$col - 1] = "true";
		} else {
			$output[$col - 1] = "false";
		}
	}
	return @output;
}

sub convert_array() {
	my $rows    = shift;
	my $cols 	= shift;
	my @pattern = @_;
	my $result  = Math::SparseMatrix->new(1, $cols);

	for (my $i = 0; $i < ($#pattern + 1); $i++) {
		if ($pattern[$i] =~ m/true/ig) {
			$result->set(1, ($i +1 ), 1);
		} else {
			$result->set(1, ($i + 1), -1);
		}
	}
	return $result;
}

sub transpose() {
	my $matrix  = shift;
	my $rows = $matrix->{_rows};
	my $cols = $matrix->{_cols};

	my $inverse = Math::SparseMatrix->new($cols, $rows);
		
	for (my $r = 1; $r <= $rows; $r++) {
		for (my $c = 1; $c <= $cols; $c++) {
			my $value = $matrix->get($r, $c);
			$inverse->set($c, $r, $value);
		}
	}
	return $inverse;
}

sub multiply() {
	my $matrix_a  = shift;
	my $matrix_b  = shift;

	my $a_rows = $matrix_a->{_rows};
	my $a_cols = $matrix_a->{_cols};

	my $b_rows = $matrix_b->{_rows};
	my $b_cols = $matrix_b->{_cols};

	my $result = Math::SparseMatrix->new($a_rows, $b_cols);

	if ($matrix_a->{_cols} != $matrix_b->{_rows}) {
		die "To use ordinary matrix multiplication the number of columns on the first matrix must mat the number of rows on the second";
	}

	for (my $result_row = 1; $result_row <= $a_rows; $result_row++) {
		for(my $result_col = 1; $result_col <= $b_cols; $result_col++) {
			my $value = 0;
			for (my $i = 1; $i <= $a_cols; $i++) {
				$value += ($matrix_a->get($result_row, $i)) * ($matrix_b->get($i, $result_col));
			}
			$result->set($result_row, $result_col, $value);
		}
	}
	return $result;
}

sub identity() {
	my $size = shift;

	if ($size < 1) {
		die "Identity matrix must be at least of size 1.";
	}
	
	my $result = Math::SparseMatrix->new ($size, $size);

	for (my $i = 1; $i <= $size; $i++) {
		$result->set($i, $i, 1);
	}
	return $result;
}

sub subtract() {
	my $matrix_a = shift;
	my $matrix_b = shift;

    my $a_rows = $matrix_a->{_rows};
    my $a_cols = $matrix_a->{_cols};

	my $b_rows = $matrix_b->{_rows};
	my $b_cols = $matrix_b->{_cols};

	if ($a_rows != $b_rows) {
		die "To subtract the matrixes they must have the same number of rows and columns.";
	}

	if ($a_cols != $b_cols) {
		die "To subtract the matrixes they must have the same number of rows and columns.  Matrix a has ";
	}

	my $result = Math::SparseMatrix->new($a_rows, $a_cols);

	for (my $result_row = 1; $result_row <= $a_rows; $result_row++) {
		for (my $result_col = 1; $result_col <= $a_cols; $result_col++) {
			my $value = ( $matrix_a->get($result_row, $result_col) ) - ( $matrix_b->get($result_row, $result_col));
			
			if ($value == 0) {
				$value += 2;
			}			
			$result->set($result_row, $result_col, $value);
		}
	}
	return $result;