Get distance of locations

Hi
I have many locations(about 1000 location)
I need calculate distance between this location
My code is :

PHP Code:

function distance($lat1, $lon1, $lat2, $lon2, $unit) {

        $theta = $lon1 - $lon2;
        $dist = sin(deg2rad($lat1)) * sin(deg2rad($lat2)) +  cos(deg2rad($lat1)) * cos(deg2rad($lat2)) * cos(deg2rad($theta));
        $dist = acos($dist);
        $dist = rad2deg($dist);
        $miles = $dist * 60 * 1.1515;
        $unit = strtoupper($unit);

        if (strtolower($unit) == "k") {
            return ($miles * 1.609344);
        } else if ($unit == "N") {
            return ($miles * 0.8684);
        } else {
            return $miles;
        }
    } 


I calculate distance between two location with foreach

PHP Code:

foreach($result as $row) {

            if ($current != NULL) {
                $distance += distance($current['latitude'],$current['longitude'],$row['latitude'],$row['longitude'],'k') ;
                $current    =   $row;
            } else {
                $current    =   $row;
            }

        } 


In each loop,i save previous location and get distance from their
But it is wrong
Does anybody can help me?

Try

PHP Code:

if (!is_null($current)) 


Or is the maths part wrong?

Try

PHP Code:

if (!is_null($current)) 


Or is the maths part wrong?

"is the maths part wrong?" what do you mean?

Try

PHP Code:

if (!is_null($current)) 


Or is the maths part wrong?

Your code did not work

"is the maths part wrong?" what do you mean?

I'm just trying to understand what part you have problem with from your original post.

As far as I can see, from the source provided, there could be only two issues - either the calculation between two points is incorrect, or you have issues with feeding in correct points.

You should try to specify what and why you think it's not working, and it'll be easier for us to help you, that's all

"is the maths part wrong?" what do you mean?

I'm just trying to understand what part you have problem with from your original post.

As far as I can see, from the source provided, there could be only two issues - either the calculation between two points is incorrect, or you have issues with feeding in correct points.

You should try to specify what and why you think it's not working, and it'll be easier for us to help you, that's all

Sorry my problem was solved
My locations not arranged by asc or desc
Thank you

Sorry my problem was solved
My locations not arranged by asc or desc
Thank you

Excellent