2levelsabove Posted April 16, 2008 Share Posted April 16, 2008 What is $dif ??????????? And why is "$query = "select * from zips where zips.lat < $lat1 AND zips.lat > $lat2 AND zips.lon < $lon1 AND zips.lon > $lon2";" used ? Please explain. Thank you!! @$zipsearch = $_GET['zipsearch']; @$radius = $_GET['radius']; $dif = '2'; $results=''; $data=array(); //if(!empty($zipsearch)){} $query = "select * from zips where zip = '$zipsearch' LIMIT 1"; $result = mysql_query($query); $row = mysql_fetch_assoc($result); if(empty($row)){$results = "<tr><td align='center' class='results' style='font-size:16px;font-weight:bold;color:red;font-family:arial;'>Invalid zip code</td></tr>";} $lat = $row['lat'];$lon = $row['lon']; $lat1 = ($lat + $dif); $lat2 = ($lat - $dif); $lon1 = ($lon + $dif); $lon2 = ($lon - $dif); $query = "select * from zips where zips.lat < $lat1 AND zips.lat > $lat2 AND zips.lon < $lon1 AND zips.lon > $lon2"; $result = mysql_query($query); while($row = mysql_fetch_assoc($result)){ $dist = great_circle_distance($lat,$row['lat'],$lon,$row['lon']); if ($dist < $radius){ array_unshift($row,$dist); $row[0]=round($row[0],2); $data[] = $row; } } sort($data); // $data now has the zip codes and distances in increasing order of distance from $_GET['zipsearch']; function great_circle_distance($lat1,$lat2,$lon1,$lon2){ /* Convert all the degrees to radians */ $lat1 = deg_to_rad($lat1); $lon1 = deg_to_rad($lon1); $lat2 = deg_to_rad($lat2); $lon2 = deg_to_rad($lon2); /* Find the deltas */ $delta_lat = $lat2 - $lat1; $delta_lon = $lon2 - $lon1; /* Find the Great Circle distance */ $temp = pow(sin($delta_lat/2.0),2) + cos($lat1) * cos($lat2) * pow(sin($delta_lon/2.0),2); $EARTH_RADIUS = 3956; $distance = $EARTH_RADIUS * 2 * atan2(sqrt($temp),sqrt(1-$temp)); return $distance; } function deg_to_rad($deg){ $radians = 0.0; $radians = $deg * M_PI/180.0; return($radians); } Quote Link to comment Share on other sites More sharing options...
stuart7398 Posted April 16, 2008 Share Posted April 16, 2008 http://www.tizag.com/phpT/variable.php Quote Link to comment Share on other sites More sharing options...
benphp Posted April 16, 2008 Share Posted April 16, 2008 What does the ampersand do? @$zipsearch = $_GET['zipsearch']; Quote Link to comment Share on other sites More sharing options...
unidox Posted April 16, 2008 Share Posted April 16, 2008 If there is an error with it, it ignores the error Quote Link to comment Share on other sites More sharing options...
haku Posted April 16, 2008 Share Posted April 16, 2008 Its actually not very good programming. Programmers put it in to suppress errors, but if the code was written properly in the first place, the errors wouldn't need to be suppressed. Error handling should be handled by writing code to handle it, not by suppressing it. Quote Link to comment Share on other sites More sharing options...
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