function num_of_neighbors($x, $y)
{
$neighbors = neighbors($x, $y);
$num = 0;
for ($i = 0; $i < 8; $i++) {
if (isset($_SESSION["world"][$neighbors[$i]["x"]][$neighbors[$i]["y"]]) && $_SESSION["world"][$neighbors[$i]["x"]][$neighbors[$i]["y"]]) {
$num++;
}
}
return $num;
}
<?php
include "../../config/settings.inc.php";
include "../../include/database.inc.php";
include "setup.php";
include "../../include/myview.php";
$t = new MyView();
$t->thispage = "iem-sites";
$t->title = "Site Neighbors";
$t->sites_current = "neighbors";
function neighbors($station, $lat, $lon)
{
$con = iemdb("mesosite");
$rs = pg_prepare($con, "_SELECT", "SELECT *,\n ST_distance(ST_transform(geom,3857), \n ST_transform(ST_GeomFromEWKT('SRID=4326;POINT(" . $lon . " " . $lat . ")'), 3857)) /1000.0 as dist from stations \n WHERE ST_point_inside_circle(geom, " . $lon . ", " . $lat . ", 0.25) \n and id != \$1 ORDER by dist ASC");
$result = pg_execute($con, "_SELECT", array($station));
$s = "<table class=\"table table-striped\">\n <thead><tr><th>Distance [km]</th><th>Network</th><th>Station Name</th></tr></thead>";
for ($i = 0; $row = @pg_fetch_assoc($result, $i); $i++) {
$s .= sprintf("<tr><td>%.3f</td><td><a href=\"locate.php?network=%s\">%s</a></td><td><a href=\"site.php?station=%s&network=%s\">%s</a></td></tr>", $row["dist"], $row["network"], $row["network"], $row["id"], $row["network"], $row["name"]);
}
$s .= "</table>";
return $s;
}
$n = neighbors($station, $metadata["lat"], $metadata["lon"]);
$t->content = <<<EOF
<h3 class="subtitle">Neighboring Stations</h3>
<p>The following is a list of IEM tracked stations within roughly 25 kilometers
from the site. Click on the site name for more information.</p>
{$n}
EOF;
$t->render('sites.phtml');
function a_star($start, $target, $map)
{
$open_heap = array($start);
// binary min-heap of indexes with values in $f
$open = array($start => TRUE);
// set of indexes
$closed = array();
// set of indexes
$g = [];
$h = [];
$f = [];
$from = [];
$g[$start] = 0;
$h[$start] = heuristic($start, $target);
$f[$start] = $g[$start] + $h[$start];
while ($open) {
$i = heap_pop($open_heap, $f);
//not yet supported
//unset($open[$i]);
$open[$i] = null;
$closed[$i] = TRUE;
if ($i == $target) {
$path = array();
for (; $i != $start; $i = $from[$i]) {
$path[myCount($path)] = $i;
}
return myArrayReverse($path);
}
foreach (neighbors($i, $map) as $j => $step) {
if (!myArrayKeyExists($j, $closed)) {
if (!myArrayKeyExists($j, $open) || $g[$i] + $step < $g[$j]) {
$g[$j] = $g[$i] + $step;
$h[$j] = heuristic($j, $target);
$f[$j] = $g[$j] + $h[$j];
$from[$j] = $i;
if (!myArrayKeyExists($j, $open)) {
$open[$j] = TRUE;
heap_push($open_heap, $f, $j);
} else {
heap_raise($open_heap, $f, $j);
}
}
}
}
}
return FALSE;
}
