compute-scottish-stv: wip debugging

[appendix-a6.git] / compute-scottish-stv

diff --git a/compute-scottish-stv b/compute-scottish-stv
index e3d5d7770a6b9f81ea701ddb58c3bd444e8dcf4c..6fde10308b409753d9f877e1df709300d2558fa3 100755 (executable)
--- a/compute-scottish-stv
+++ b/compute-scottish-stv
@@ -4,6 +4,9 @@
 # The Scottish Local Government Elections Order 2007
 
 use strict;
 # The Scottish Local Government Elections Order 2007
 
 use strict;

+use Carp;
+use Data::Dumper;
+use Math::BigRat;

 use bigrat;
 
 # Data structures:
 use bigrat;
 
 # Data structures:


@@ -29,6 +32,18 @@ our $stage=0;
 our $quota;
 our %tie;
 
 our $quota;
 our %tie;
 

+open DEBUG, ">.compute.log" or die $!;
+DEBUG->autoflush(1);
+
+$SIG{__WARN__} = sub {
+    print DEBUG Dumper(\%tie,
+                      \@non_transferable,
+                      \%cands,
+                      \@allvotes,
+                      $stage, $quota);
+    confess $_[0];
+};
+

 sub unkopt ($$) {
     my ($what,$opt) = @_;
     if ($opt =~ m/^[A-Z]/) {
 sub unkopt ($$) {
     my ($what,$opt) = @_;
     if ($opt =~ m/^[A-Z]/) {


@@ -55,12 +70,12 @@ for (;;) {
            }
        }
     } elsif (m/^(\w+) = (\S*) \|/) {
            }
        }
     } elsif (m/^(\w+) = (\S*) \|/) {

-       my ($cand,$desc) = @_;
+       my ($cand,$desc) = ($1,$2);

        unkopt "candidate $cand", $_ foreach split / /, $';
        $cands{$cand}{Desc} = $desc;
     } elsif (m/^(\w*) :\s*(.*)\s*\|(.*)/) {
        my ($voter,$prefs,$opts) = ($1,$2,$3);
        unkopt "candidate $cand", $_ foreach split / /, $';
        $cands{$cand}{Desc} = $desc;
     } elsif (m/^(\w*) :\s*(.*)\s*\|(.*)/) {
        my ($voter,$prefs,$opts) = ($1,$2,$3);

-       my $v = { Voter => $voter };
+       my $v = { Voter => $voter, Prefs => [ ] };

        push @{ $v->{Prefs} }, [ $_ =~ m/\w+/g ]
            foreach split /\s+/, $prefs;
        foreach $_ (split / /, $opts) {
        push @{ $v->{Prefs} }, [ $_ =~ m/\w+/g ]
            foreach split /\s+/, $prefs;
        foreach $_ (split / /, $opts) {


@@ -81,12 +96,15 @@ for (;;) {
 }
 
 $cands{$_}{Cand} = $_ foreach keys %cands;
 }
 
 $cands{$_}{Cand} = $_ foreach keys %cands;

+$_->{Weight} //= 1/1 foreach @allvotes;
+$_->{TransferredSurplus} //= [ ] foreach @allvotes;

 
 sub votelog ($$) {
     my ($vote,$m) = @_;
     push @{ $vote->{Log} }, "stage $stage: $m";
 }
 
 
 sub votelog ($$) {
     my ($vote,$m) = @_;
     push @{ $vote->{Log} }, "stage $stage: $m";
 }
 

+sub sortballots (@);

 sub sortballots (@) {
     # Takes each argument, which should be a ballot, sorts
     # it into $cand{CAND}{Votes} according to first preference.
 sub sortballots (@) {
     # Takes each argument, which should be a ballot, sorts
     # it into $cand{CAND}{Votes} according to first preference.


@@ -118,7 +136,7 @@ sub sortballots (@) {
        my $noncont = $c->{NonCont};
        if ($noncont) {
            votelog $v, "dropping pref $fp, $noncont";
        my $noncont = $c->{NonCont};
        if ($noncont) {
            votelog $v, "dropping pref $fp, $noncont";

-           sortvallots $v;
+           sortballots $v;

            next;
        }
        votelog $v, "sorted into pile for candidate $fp weight $w";
            next;
        }
        votelog $v, "sorted into pile for candidate $fp weight $w";


@@ -128,7 +146,7 @@ sub sortballots (@) {
 
 sub prf {
     my $fmt = shift;
 
 sub prf {
     my $fmt = shift;

-    printf "stage %d: ".$_, $stage, @_;
+    printf "stage %d: ".$fmt, $stage, @_;

 }
 
 sub countballots () {
 }
 
 sub countballots () {


@@ -136,22 +154,23 @@ sub countballots () {
        my $c = $cands{$cand};
        next if $c->{NonCont};
        $c->{Total} = 0;
        my $c = $cands{$cand};
        next if $c->{NonCont};
        $c->{Total} = 0;

-       $c->{Total} += $_->{Weight} foreach @{ $c->{Voters} };
-       prf "cand %s: %s votes\n", $stage, $cand, $c->{Total};
+       $c->{Total} += $_->{Weight} foreach @{ $c->{Votes} };
+       prf "candidate %-10s: %10s votes\n", $cand, $c->{Total};

        $c->{History}[$stage-1] = $c->{Total};
     }
 }
 
 sub computequota () {
     my $totalvalid = 0;
        $c->{History}[$stage-1] = $c->{Total};
     }
 }
 
 sub computequota () {
     my $totalvalid = 0;

-    $totalvalid += $_->{Total} foreach keys %cands;
-    $quota = floor($totalvalid / (1 + $seats));
+    $totalvalid += $_->{Total} foreach values %cands;
+    $quota = ($totalvalid / (1 + $seats)) -> bfloor();
+    prf "quota %10s\n", $quota;

 }
 
 sub total_history_cmp () {
     my $ha = $a->{History};
     my $hb = $b->{History};
 }
 
 sub total_history_cmp () {
     my $ha = $a->{History};
     my $hb = $b->{History};

-    foreach my $s (reverse 1 .. $stage) {
+    foreach my $s (reverse 0 .. $stage-1) {

        my $d = $ha->[$s] <=> $hb->[$s];
        next unless $d;
        print DEBUG "history cmp $a->{Cand} $b->{Cand}".
        my $d = $ha->[$s] <=> $hb->[$s];
        next unless $d;
        print DEBUG "history cmp $a->{Cand} $b->{Cand}".


@@ -206,13 +225,14 @@ sub select_best_worst ($$$$) {
     if ($nequal > 1) {
        my @all = map { $_->{Cand} } @maybe[0 .. $nequal-1];
        my $tiekey = $signum > 0 ? 'Win' : 'Lose';
     if ($nequal > 1) {
        my @all = map { $_->{Cand} } @maybe[0 .. $nequal-1];
        my $tiekey = $signum > 0 ? 'Win' : 'Lose';

-       my $win = $tie{"@all"}{$tiekey};
-       die "need tie break, want $tiekey from @all" unless defined $win;
+       $selectcand = $tie{"@all"}{$tiekey};
+       die "need tie break, want $tiekey from @all"
+           unless defined $selectcand;

        prf "$what %s due to tie break amongst %s\n",
            $selectcand, "@all";
     } else {
        prf "$what %s due to tie break amongst %s\n",
            $selectcand, "@all";
     } else {

-       $selectcand = $maybe[0];
-       prf "$what %s\n";
+       $selectcand = $maybe[0]{Cand};
+       prf "$what %s\n", $selectcand;

     }
 
     return $cands{$selectcand};
     }
 
     return $cands{$selectcand};


@@ -224,13 +244,17 @@ sub elect_core ($) {
     $c->{NonCont} = 'Elected';
 }
 
     $c->{NonCont} = 'Elected';
 }
 

+$stage = 1;
+

 sortballots @allvotes;
 sortballots @allvotes;

+countballots();
+computequota();

 
 for (;;) {
     $stage++;
 
     my $seats_remain = $seats
 
 for (;;) {
     $stage++;
 
     my $seats_remain = $seats

-       - grep { $_->{NonCont} eq 'Elected' } values %cands;
+       - grep { ($_->{NonCont} // '') eq 'Elected' } values %cands;

     if (continuing() <= $seats_remain) {
        foreach my $c (continuing()) {
            prf "electing %s to fill remaining place(s)\n", $c->{Cand};
     if (continuing() <= $seats_remain) {
        foreach my $c (continuing()) {
            prf "electing %s to fill remaining place(s)\n", $c->{Cand};


@@ -258,16 +282,30 @@ for (;;) {
            next;
        }
 
            next;
        }
 

-       my $B = $c->{Weight};
+       my $B = $c->{Total};
+       my %tspr;
+
+       prf "surplus %10s\n", $surplus;

 
        foreach my $v (@{ $c->{Votes} }) {
 
        foreach my $v (@{ $c->{Votes} }) {

+           my $previously = $v->{TransferredSurplus};
+           push @$previously, $c->{Cand};
+

            my $A = $surplus * $v->{Weight};
            my $F = 100000;
            my $A = $surplus * $v->{Weight};
            my $F = 100000;

-           my $xfervalue = floor(($A * $F) / $B) / $F;
+           my $xfervalue = ((($A * $F) / $B) -> bfloor() ) / $F;

            # SLGEO 48(3): we do arithmetic to 5 d3ecimal places,
            # but always rounding down
            votelog $v, "transferring with value $xfervalue (A=$A B=$B)";
            $v->{Weight} = $xfervalue;
            # SLGEO 48(3): we do arithmetic to 5 d3ecimal places,
            # but always rounding down
            votelog $v, "transferring with value $xfervalue (A=$A B=$B)";
            $v->{Weight} = $xfervalue;

+
+           if (defined $tspr{"@$previously"}) {
+               die unless $tspr{"@$previously"} == $xfervalue;
+           } else {
+               $tspr{"@$previously"} = $xfervalue;
+               prf "transfer value of ballots %s: %10s\n",
+                   "@$previously", $xfervalue;
+           }

            sortballots $v;
        }
        $c->{Votes} = { }; # will crash if we access it again
            sortballots $v;
        }
        $c->{Votes} = { }; # will crash if we access it again