PHP to achieve the search location and calculate the two-point geographical distance between the instance _php instance

Source: Internet
Author: User
Tags auth cos mongodb pow sin

Location Search
LBS, store latitude and longitude coordinates for each location, search for nearby locations, and establish a geographical index to improve query efficiency.
MongoDB Geographical Index, 2d and 2dsphere, corresponding plane and spherical surface.

1. Create lbs set storage location coordinates

use lbs; 
 
Db.lbs.insert ( 
  { 
    loc:{ 
      type: "point", 
      coordinates: [113.332264, 23.156206] 
    }, 
    name: "Guangzhou East station" 
  } 
) 
 
Db.lbs.insert ( 
  { 
    loc:{ 
      type: "point", 
      coordinates: [113.330611, 23.147234] 
    }, 
    name: "Forest and West" 
  } 
) 
 
Db.lbs.insert ( 
  { 
    loc:{ 
      type: "point", 
      coordinates: [113.328095, 23.165376] 
    }, 
    name: "Balance Rack" 
  } 
) 

2. Create a geographical index

Db.lbs.ensureIndex ( 
  { 
    loc: "2dsphere" 
  } 
) 

3. Query the coordinates near
The current location is: Times Square,
Coordinate:

113.323568, 23.146436

Search for points within a kilometer, sorted from near to far

Db.lbs.find 
  { 
    loc: {$near: { 
        $geometry: { 
          type: "point", 
          coordinates: [113.323568, 23.146436] 
        }, 
        $maxDistance: 1000 
      } 
    } 
) 

Search results:

Copy Code code as follows:

{"_id": ObjectId ("556a651996f1ac2add8928fa"), "loc": {"type": "Point", "coordinates": [113.330611, 23.147234]}, " Name ": Forest and West"}

The PHP code is as follows:

<?php//Connection MONGODB function conn ($dbhost, $dbname, $dbuser, $dbpasswd) {$server = ' mongodb://'. $dbuser. $dbpas SWD. ' @ '. $dbhost. ' 
  /'. $dbname; 
    try{$conn = new Mongoclient ($server); 
  $db = $conn->selectdb ($dbname); The catch (Mongoexception $e) {throw new errorexception (' Unable to connect to DB server. Error: '. 
  $e->getmessage (), 31); 
return $db; //Insert coordinates to MongoDB function add ($dbconn, $tablename, $longitude, $latitude, $name) {$index = array (' loc ' => ' 2dsphe 
  Re '); $data = Array (' loc ' => array (' type ' => ' point ', ' coordinates ' => array ($ 
  Longitude), Doubleval ($latitude))), ' name ' => $name); 
  $coll = $dbconn->selectcollection ($tablename); 
  $coll->ensureindex ($index); 
  $result = $coll->insert ($data, Array (' W ' => true)); Return (Isset ($result [' OK ']) &&!empty ($result [' OK ']))? 
True:false; //Search Nearby coordinates function query ($dbconn, $tablenamE, $longitude, $latitude, $maxdistance, $limit =10) {$param = array (' loc ' => Array (' $nearSphere ' => Array (' $geometry ' => array (' type ' => ' point ', ' coordinates ' => array doubleval ($ 
 
  Longitude), Doubleval ($latitude)), ' $maxDistance ' => $maxdistance *1000)); 
  $coll = $dbconn->selectcollection ($tablename); 
  $cursor = $coll->find ($param); 
   
  $cursor = $cursor->limit ($limit); 
  $result = Array (); 
  foreach ($cursor as $v) {$result [] = $v; 
return $result; 
 
$DB = conn (' localhost ', ' lbs ', ' root ', ' 123456 '); 
  Randomly insert 100 coordinate records for ($i =0 $i <100; $i + +) {$longitude = ' 113.3 '. Mt_rand (10000, 99999); 
  $latitude = ' 23.15 '. Mt_rand (1000, 9999); 
  $name = ' name '. Mt_rand (10000,99999); 
Add ($db, ' lbs ', $longitude, $latitude, $name); 
//Search for a point within a kilometer $longitude = 113.323568; 
$latitude = 23.146436; 
$maxdistance = 1; $result = Query ($db, ' lbs ', $longitUde, $latitude, $maxdistance); 
Print_r ($result); 

 ?>

To demonstrate PHP code, you first need to create users and execute auth in MongoDB's lbs. The method is as follows:

use lbs; 
Db.createuser ( 
  { 
    "user": "Root", 
    "pwd": "123456", 
    "roles": [] 
  } 
) 
 
Db.auth ( 
  { 
    "user": "Root", 
    "pwd": "123456" 
  } 
) 

Calculate the distance of two-point geographical coordinates
function: Calculate the spherical distance between two points according to the longitude and latitude of pi and earth radius coefficient and two point coordinate.


Get two-point coordinate distance:

<?php/** * Calculates the distance between two-point geographical coordinates * @param decimal $longitude 1 beginning Longitude * @param decimal $latitude 1 beginning latitude * @param decimal $lon
 Gitude2 End Longitude * @param Decimal $latitude 2 End latitude * @param Int $unit Unit 1: M 2: km * @param int $decimal precision reserved decimal places * @return Decimal */function Getdistance ($longitude 1, $latitude 1, $longitude 2, $latitude 2, $unit =2, $decimal =2) {$EAR Th_radius = 6370.996;

  The earth radius coefficient $PI = 3.1415926;
  $radLat 1 = $latitude 1 * $PI/180.0;

  $radLat 2 = $latitude 2 * $PI/180.0;
  $radLng 1 = $longitude 1 * $PI/180.0;

  $radLng 2 = $longitude 2 * $PI/180.0;
  $a = $radLat 1-$radLat 2;

  $b = $radLng 1-$radLng 2;
  $distance = 2 * ASIN (SQRT (POW) (sin ($a/2), 2) + cos ($radLat 1) * cos ($radLat 2) * POW (sin ($b/2), 2));

  $distance = $distance * $EARTH _radius * 1000;
  if ($unit ==2) {$distance = $distance/1000;

Return round ($distance, $decimal);
///start coordinates $longitude 1 = 113.330405;

$latitude 1 = 23.147255;
The endpoint coordinates $longitude 2 = 113.314271;

$latitude 2 = 23.1323; $distance = Getdistance ($longitude 1, $latitude 1, $longitude 2, $latitude 2, 1); echo $distance. ' m ';
2342.38m $distance = getdistance ($longitude 1, $latitude 1, $longitude 2, $latitude 2, 2); Echo $distance. ' Km ';

 2.34km?>

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