compute-scottish-stv: --sort=alpha

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

diff --git a/compute-scottish-stv b/compute-scottish-stv
index d92db96382bddeac989202ad6e937ca8f52f6ce6..81dc6adeafb10d553c50b2153a250a530bfc8966 100755 (executable)
--- a/compute-scottish-stv
+++ b/compute-scottish-stv
@@ -31,6 +31,10 @@ our %cands;
 our $stage=0;
 our $quota;
 our %tie;
+our @elected;
+
+our $DIGS = 5;
+our $F = (new Math::BigRat 10)->bpow($DIGS);
 
 open DEBUG, ">.compute.log" or die $!;
 DEBUG->autoflush(1);
@@ -54,6 +58,8 @@ $SIG{__DIE__} = sub {
     die $_[0];
 };
 
+sub total_history_cmp ();
+
 sub unkopt ($$) {
     my ($what,$opt) = @_;
     if ($opt =~ m/^[A-Z]/) {
@@ -63,6 +69,19 @@ sub unkopt ($$) {
     }
 }
 
+my $display_cmp = \&total_history_cmp;
+
+while (@ARGV && $ARGV[0] =~ m/^\-/) {
+    $_ = shift @ARGV;
+    if (m/^--$/) {
+       last;
+    } elsif (m/^--sort=alpha$/) {
+       $display_cmp = sub { $b->{Cand} cmp $a->{Cand} };
+    } else {
+       die;
+    }
+}
+
 for (;;) {
     $_ = <>;
     if (m/^\| /) {
@@ -156,6 +175,30 @@ sub sortballots (@) {
     }
 }
 
+sub floor ($) {
+    my ($v) = @_;
+    $v = new Math::BigRat $v; # we need a copy
+    return $v->bfloor();
+}
+
+sub sv ($) {
+    my ($in) = @_;
+    my $v = new Math::BigRat $in; # just in case
+    my $intpart = floor($v);
+    my $frac = $v - $intpart;
+    my $good = floor($frac * $F);
+    my $bad = $frac * $F - $good;
+    my $s = sprintf "%7d", $intpart;
+    if ($frac) {
+       $s .= sprintf ".%0${DIGS}d", $good;
+       $s .= sprintf "%-4s", ($bad ? "+$bad" : "");
+    } else {
+       $s .= sprintf " %${DIGS}s%4s", '', '';
+    }
+#print STDERR "# $in => $s # (intpart=$intpart frac=$frac)\n";
+    return $s;
+}
+
 sub prf {
     my $fmt = shift;
     printf "stage %d: ".$fmt, $stage, @_;
@@ -170,17 +213,17 @@ sub countballots () {
        $c->{History}[$stage-1] = $c->{Total};
     }
 
-    foreach my $c (reverse sort total_history_cmp
+    foreach my $c (reverse sort $display_cmp
                   grep { !$_->{NonCont} } values %cands) {
-       prf "candidate %-10s: %10s votes\n", $c->{Cand}, $c->{Total};
+       prf "candidate %-10s: %s votes\n", $c->{Cand}, sv $c->{Total};
     }
 }
 
 sub computequota () {
     my $totalvalid = 0/1;
     $totalvalid += $_->{Total} foreach values %cands;
-    $quota = ($totalvalid / (1 + $seats)) -> bfloor();
-    prf "quota %10s\n", $quota;
+    $quota = floor($totalvalid / (1 + $seats) + 1);
+    prf "total valid %s quota %s\n", (sv $totalvalid), (sv $quota);
 }
 
 sub total_history_cmp () {
@@ -261,6 +304,7 @@ sub elect_core ($) {
     my ($c) = @_;
     prf "*** ELECT %s \`%s' ***\n", $c->{Cand}, $c->{Desc};
     $c->{NonCont} = 'Elected';
+    push @elected, $c;
 }
 
 $stage = 0;
@@ -270,8 +314,12 @@ for (;;) {
 
     sortballots @allvotes if $stage == 1;
 
-    my $seats_remain = $seats
-       - grep { ($_->{NonCont} // '') eq 'Elected' } values %cands;
+    my $seats_remain = $seats - @elected;
+
+    prf "seats remaining %d\n", $seats_remain;
+
+    last unless $seats_remain;
+
     if (continuing() <= $seats_remain) {
        foreach my $c (continuing()) {
            prf "electing %s to fill remaining place(s)\n", $c->{Cand};
@@ -301,18 +349,19 @@ for (;;) {
            next;
        }
 
+       last if $seats_remain == 1; # don't bother doing more transfers
+
        my $B = $c->{Total};
        my %tspr;
 
-       prf "surplus %10s\n", $surplus;
+       prf "surplus %s\n", sv $surplus;
 
        foreach my $v (@{ $c->{Votes} }) {
            my $previously = $v->{TransferredSurplus};
            push @$previously, $c->{Cand};
 
            my $A = $surplus * $v->{Weight};
-           my $F = 100000;
-           my $xfervalue = ((($A * $F) / $B) -> bfloor() ) / $F;
+           my $xfervalue = floor(($A * $F) / $B) / $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)";
@@ -322,8 +371,8 @@ for (;;) {
                die unless $tspr{"@$previously"} == $xfervalue;
            } else {
                $tspr{"@$previously"} = $xfervalue;
-               prf "transfer value of ballots %s: %10s\n",
-                   "@$previously", $xfervalue;
+               prf "transfer value of ballots %20s: %s\n",
+                   "@$previously", sv $xfervalue;
            }
        }
        sortballots @{ $c->{Votes} };
@@ -349,4 +398,11 @@ for (;;) {
     die;
 }
 
-print "done.\n"; 
+print "Winners:\n"; 
+
+foreach my $i (0..$#elected) {
+    my $c = $elected[$i];
+    printf " %3d. %-10s %s\n", $i+1, $c->{Cand}, $c->{Desc};
+}
+
+print "done.\n";