+}
+
+sub get_players_and_ratings {
+ my ($dbh, $season, $division, $subdivision) = @_;
+
+ my $q = $dbh->prepare('SELECT fotballdeltagere.id,fotballdeltagere.navn,rating,rating_stddev FROM fotballdeltagere JOIN fotballserier ON fotballdeltagere.serie=fotballserier.nr LEFT JOIN ratings ON fotballdeltagere.id=ratings.id WHERE sesong=? AND divisjon=? AND avdeling=?');
+ $q->execute($season, $division, $subdivision);
+
+ while (my $ref = $q->fetchrow_hashref) {
+ my $id = $ref->{'id'};
+ $players{$id} = sanitize(Encode::decode_utf8($ref->{'navn'}));
+ $ratings{$id} = $ref->{'rating'};
+ $ratings_stddev{$id} = $ref->{'rating_stddev'};
+ }
+ $q->finish;
+}
+
+sub get_matches {
+ my ($dbh, $season, $division, $subdivision) = @_;
+
+ my @matches = ();
+ my $q = $dbh->prepare('
+ SELECT
+ d1.id AS p1, d2.id AS p2, maalfor AS score1, maalmot AS score2
+ FROM fotballresultater r
+ JOIN fotballserier s ON r.serie=s.nr
+ JOIN fotballdeltagere d1 ON r.lagrecno=d1.nr AND r.serie=d1.serie
+ JOIN fotballdeltagere d2 ON r.motstander=d2.nr AND r.serie=d2.serie
+ WHERE
+ sesong=? AND divisjon=? AND avdeling=?
+ AND lagrecno > motstander
+ ');
+ $q->execute($season, $division, $subdivision);
+
+ while (my $ref = $q->fetchrow_hashref) {
+ push @matches, [ $ref->{'p1'}, $ref->{'p2'}, $ref->{'score1'}, $ref->{'score2'} ];
+ }
+ $q->finish;
+
+ return @matches;
+}
+
+sub get_covariance_matrix {
+ my ($dbh, @players) = @_;
+
+ my $player_sql = '{' . join(',', @players ) . '}';
+ my $q = $dbh->prepare('SELECT * FROM covariance WHERE player1=ANY(?::smallint[]) AND player2=ANY(?::smallint[])', { pg_prepare_now => 0 });
+ $q->execute($player_sql, $player_sql);
+
+ my $cov = {};
+ while (my $ref = $q->fetchrow_hashref) {
+ $cov->{$ref->{'player1'}}{$ref->{'player2'}} = $ref->{'cov'};
+ }
+
+ return $cov;
+}
+
+sub write_parms_to_file {
+ my ($aux_parms, $match_stddev, $used_ratings, $used_cov) = @_;