#!/usr/bin/perl -w
# Post-processing of ascii boundary files from
#     http://www.census.gov/geo/www/tiger/
# Assume the data has previously been processed by
#     perl -pe 's/\S+\s+\S+\s+\S+//; s/END//'
# This script removes close-by points and reduces the number of
# significant digits.

use strict;
my ($line, $close, $x, $prev);
my ($resolution) = 0.03;

sub dist {
    my ($p, $q) = @_;
    my ($s, $t);
    $s = $p->[0] - $q->[0];
    $t = $p->[1] - $q->[1];
    return sqrt($s*$s+$t*$t);
}

while (<>) {
    if (/^\s*$/) {
	if (defined $close) {
	    printf "%8.2f %8.2f\n", @$close;
	    undef $close;
	}
	undef $prev;
	print "\n";
	next;
    }
    $x = [split " "];
    if (defined $prev) {
	next if dist($prev, $x) < $resolution;
    } else {
	$close = [@$x];
    }
    printf "%8.2f %8.2f\n", @$x;
    $prev = $x;
}