I have coordinates pool with x,y combniation I need to match nearest match of given x,y

Question

Example

1   8.919280,45.622651  
2   8.910296,45.626021  
3   8.914084,45.627028  
4   8.913913,45.62941  

I have to match x,y not sum of x and y but closest of x and y. not closest of (x+y) or ((x1-x)+(y1-y)) both are wrong I need perfect match.

8.912680,45.629392

foreach($pair_coordinates as $pair_coordinate)
                    {
                    sscanf((string)$pair_coordinate, '%f,%f',$longitude, $latitude);
                        $data[$move]['lng'] = $longitude;
                        $data[$move]['lat'] = $latitude;
                        $data[$move]['longitude'] = ($longitude-$_POST['k_lng']);
                        $data[$move]['latitude'] = ($latitude-$_POST['k_lat']);

                        $data[$move]['diff'] = $data[$move]['longitude'] + $data[$move]['latitude'];

                        $data[$move]['diff'] = abs($data[$move]['diff']);

                        $sort[$move] = $data[$move]['diff'];
                        $sort_old[$move] = $data[$move]['diff'];

                        $data[$move]['zona'] = (string)$placemarker->ExtendedData->Data[2]->value;
                        $data[$move]['codcom'] = (string)$placemarker->ExtendedData->Data[1]->value;
                        $data[$move]['markername'] = (string)$placemarker->name;
                        if($data[$move]['longitude'] < 0 || $data[$move]['latitude'] < 0)
                        {
                            unset($sort[$move]);
                        }


                        $move++;
                    }







                    asort($sort);

Answer 1

Maybe this will help you get on track:

<?php

$coords = array(
    array("lng" => 8.919280, "lat" => 45.622651),
    array("lng" => 8.910296, "lat" => 45.626021),
    array("lng" => 8.914084, "lat" => 45.627028),
    array("lng" => 8.913913, "lat" => 45.62941)
);

$find = array("lng" => 8.912680, "lat" => 45.629392);

$idx = null;
$shortest = null;

foreach($coords as $k => $v)
{
    // I know the abs() calls are optional, but this allows for some other logic to be used on the individual distances aswell.
    $dLng = abs($find["lng"] - $v["lng"]); 
    $dLat = abs($find["lat"] - $v["lat"]);

    $distance = sqrt($dLng * $dLng + $dLat * $dLat);

    if (!$shortest || $distance < $shortest)
    {
        $shortest = $distance;
        $idx = $k;
    }
}

if ($idx)
{
    echo "Found:\n";
    print_r($coords[$idx]);
} else {
    echo "Nothing found.";
}

Output:

Found:
Array
(
    [lng] => 8.913913
    [lat] => 45.62941
)

Another solution using array_reduce:

<?php

$coords = array(
    array("lng" => 8.919280, "lat" => 45.622651),
    array("lng" => 8.910296, "lat" => 45.626021),
    array("lng" => 8.914084, "lat" => 45.627028),
    array("lng" => 8.913913, "lat" => 45.62941)
);

$find = array("lng" => 8.912680, "lat" => 45.629392);

function distance($a, $b)
{
    $dLng = abs($a["lng"] - $b["lng"]);
    $dLat = abs($a["lat"] - $b["lat"]);

    $distance = sqrt($dLng * $dLng + $dLat * $dLat);

    return $distance;
}


$nearest = array_reduce($coords, function($carry, $item) use ($find)
{
    if (!$carry)
        return $item;

    $dCarry = distance($find, $carry);
    $dItem = distance($find, $item);

    return $dCarry < $dItem ? $carry : $item;
}, null);

print_r($nearest);

Output:

Array
(
    [lng] => 8.913913
    [lat] => 45.62941
)