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Zip Code Locator Hack Question


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#1 kewl132

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Posted 10 April 2006 - 04:37 PM

I am in the process of hacking a dealer/zipcode locator script and have ran into a roadblock. I need the script to display the returned results sorted by the distance.

you can view the demo I have up at www.jonstober.com/demo.php

I think I just need to sort the array returned by get_zips_in_range function before I display it but I am not sure how to do this?

Here is the code that I am using

<?

class zipcode_class {

   var $last_error = "";            // last error message set by this class
   var $last_time = 0;              // last function execution time (debug info)
   var $units = "m";                // m = miles, k = kilometers
   var $decimals = 2;               // decimal places for returned distance


   function get_zip_details($zip) {
      
      // This function pulls the details from the database for a
      // given zip code.

      $sql = "SELECT lattitude, longitude, city, state.state_prefix, state_name,
              zip_class, station from zip_code, state
              WHERE zip_code=$zip
              AND zip_code.state_prefix=state.state_prefix";
              
      $r = mysql_query($sql);
      if (!$r) {
         $this->last_error = mysql_error();
         return;
      } else {
         $row = mysql_fetch_array($r, MYSQL_ASSOC);
         mysql_free_result($r);
         return $row;       
      }
   }

   function get_zip_point($zip) {
   
      // This function pulls just the lattitude and longitude from the
      // database for a given zip code.
      
      $sql = "SELECT lattitude, longitude from zip_code WHERE zip_code=$zip";
      $r = mysql_query($sql);
      if (!$r) {
         $this->last_error = mysql_error();
         return;
      } else {
         $row = mysql_fetch_array($r);
         mysql_free_result($r);
         return $row;       
      }      
   }
   
   function calculate_mileageA($lat1, $lat2, $lon1, $lon2) {
      
      // This function is not used right now.  This is based on code found
      // all over the internet such as 4guysfromrolla.com.  It's not clear
      // who the original author was.
      
      $dist = sin(deg2rad($lat1)) * sin(deg2rad($lat2));
      $dist = $dist+cos(deg2rad($lat1))*cos(deg2rad($lat2))*cos(deg2rad($lon1 - $lon2));
      $dist = acos($dist);
      $dist = rad2deg($dist);
      return $dist * 60 * 1.1515;
   }

   function calculate_mileage($lat1, $lat2, $lon1, $lon2) {

      // used internally, this function actually performs that calculation to
      // determine the mileage between 2 points defined by lattitude and
      // longitude coordinates.  This calculation is based on the code found
      // at http://www.cryptnet.net/fsp/zipdy/
       
      // Convert lattitude/longitude (degrees) to radians for calculations
      $lat1 = deg2rad($lat1);
      $lon1 = deg2rad($lon1);
      $lat2 = deg2rad($lat2);
      $lon2 = deg2rad($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);
      $distance = 3956 * 2 * atan2(sqrt($temp),sqrt(1-$temp));

      return $distance;
   }
   
   function get_zips_in_range($zip, $range) {
       
      // returns an array of the zip codes within $range of $zip. Returns
      // an array with keys as zip codes and values as the distance from
      // the zipcode defined in $zip.
      
      
      $details = $this->get_zip_point($zip);  // base zip details
      if (empty($details)) return;
      
      // This portion of the routine  calculates the minimum and maximum lat and
      // long within a given range.  This portion of the code was written
      // by Jeff Bearer (http://www.jeffbearer.com). This significanly decreases
      // the time it takes to execute a query.  My demo took 3.2 seconds in
      // v1.0.0 and now executes in 0.4 seconds!  Greate job Jeff!
      
      // Find Max - Min Lat / Long for Radius and zero point and query
      // only zips in that range.
      $lat_range = $range/69.172;
      $lon_range = abs($range/(cos($details[0]) * 69.172));
      $min_lat = number_format($details[0] - $lat_range, "4", ".", "");
      $max_lat = number_format($details[0] + $lat_range, "4", ".", "");
      $min_lon = number_format($details[1] - $lon_range, "4", ".", "");
      $max_lon = number_format($details[1] + $lon_range, "4", ".", "");
      

      $return = array();    // declared here for scope


      $sql = "SELECT * FROM zip_code
              WHERE szip = zip_code AND lattitude BETWEEN '$min_lat' AND
             '$max_lat' AND longitude BETWEEN '$min_lon' AND '$max_lon' LIMIT 3";
             
      $r = mysql_query($sql);
      
      if (!$r) {    // sql error
      
         $this->last_error = mysql_error();
         return;
         
      } else {
          
         while ($row = mysql_fetch_row($r)) {
   
            // loop through all 40 some thousand zip codes and determine whether
            // or not it's within the specified range.
            
            $dist = $this->calculate_mileage($details[0],$row[1],$details[1],$row[2]);
            if ($this->units == 'k') $dist = $dist * 1.609344;
            if ($dist <= $range) {
               $return[str_pad($row[0], 5, "0", STR_PAD_LEFT)] = round($dist, $this->decimals);
            }
         }
         mysql_free_result($r);
      }
      
          
      return $return;
   }

   function chronometer()  {

   // chronometer function taken from the php manual.  This is used primarily
   // for debugging and anlyzing the functions while developing this class.  
  
   $now = microtime(TRUE);  // float, in _seconds_
   $now = $now + time();
   $malt = 1;
   $round = 7;
  
   if ($this->last_time > 0) {
       /* Stop the chronometer : return the amount of time since it was started,
       in ms with a precision of 3 decimal places, and reset the start time.
       We could factor the multiplication by 1000 (which converts seconds
       into milliseconds) to save memory, but considering that floats can
       reach e+308 but only carry 14 decimals, this is certainly more precise */
      
       $retElapsed = round($now * $malt - $this->last_time * $malt, $round);
      
       $this->last_time = $now;
      
       return $retElapsed;
   } else {
       // Start the chronometer : save the starting time
    
       $this->last_time = $now;
      
       return 0;
   }
}

}


#2 ober

ober
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Posted 10 April 2006 - 07:59 PM

It may be as simple as using an ORDER BY clause to your SQL statement.

Info: PHP Manual





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