Getting all vertex lat, long coordinates every 1 meter between two known points using PHP?

This is quick and dirty. Most of this was adapted from the following website:

http://www.movable-type.co.uk/scripts/latlong.html

I haven't tested this too much but it seemed to work after initial testing. It will return a list of lat, long coordinate pairs along a line at a specified interval. I wrote it in python since I don't know php very well.

from math import cos, sin, atan2, sqrt, radians, degrees, asin, modf

def getPathLength(lat1,lng1,lat2,lng2):
    '''calculates the distance between two lat, long coordinate pairs'''
    R = 6371000 # radius of earth in m
    lat1rads = radians(lat1)
    lat2rads = radians(lat2)
    deltaLat = radians((lat2-lat1))
    deltaLng = radians((lng2-lng1))
    a = sin(deltaLat/2) * sin(deltaLat/2) + cos(lat1rads) * 
        cos(lat2rads) * sin(deltaLng/2) * sin(deltaLng/2)
    c = 2 * atan2(sqrt(a), sqrt(1-a))
    d = R * c

    return d

def getDestinationLatLong(lat,lng,azimuth,distance):
    '''returns the lat an long of destination point 
    given the start lat, long, aziuth, and distance'''
    R = 6378.1 #Radius of the Earth in km
    brng = radians(azimuth) #Bearing is degrees converted to radians.
    d = distance/1000 #Distance m converted to km

    lat1 = radians(lat) #Current dd lat point converted to radians
    lon1 = radians(lng) #Current dd long point converted to radians

    lat2 = asin( sin(lat1) * cos(d/R) + cos(lat1)* sin(d/R)* cos(brng))

    lon2 = lon1 + atan2(sin(brng) * sin(d/R)* cos(lat1), 
           cos(d/R)- sin(lat1)* sin(lat2))

    #convert back to degrees
    lat2 = degrees(lat2)
    lon2 = degrees(lon2)

    return[lat2, lon2]

def main(interval,azimuth,lat1,lng1,lat2,lng2):
    '''returns every coordinate pair inbetween two coordinate 
    pairs given the desired interval'''
    coords = []
    d = getPathLength(lat1,lng1,lat2,lng2)
    remainder, dist = modf((d / interval))
    counter = 1.0
    coords.append([lat1,lng1])
    for distance in xrange(1,int(dist)):
        c = getDestinationLatLong(lat1,lng1,azimuth,counter)
        counter += 1.0
        coords.append(c)
    counter +=1
    coords.append([lat2,lng2])
    return coords

if __name__ == "__main__":
    #point interval in meters
    interval = 1
    #direction of line in degrees
    azimuth = 279.91
    #start point
    lat1 = 41.97809
    lng1 = -91.65573
    #end point
    lat2 = 41.97834
    lng2 = -91.65767
    coords = main(interval,azimuth,lat1,lng1,lat2,lng2)
    print coords

I hope this helps. sorry if not. :)

Ok, I added the ability for it to calculate the azimuth for you. I tested with the same location you were using and it turned out perfectly.http://www.darrinward.com/lat-long/?id=705140

import math

def getPathLength(lat1,lng1,lat2,lng2):
    '''calculates the distance between two lat, long coordinate pairs'''
    R = 6371000 # radius of earth in m
    lat1rads = math.radians(lat1)
    lat2rads = math.radians(lat2)
    deltaLat = math.radians((lat2-lat1))
    deltaLng = math.radians((lng2-lng1))
    a = math.sin(deltaLat/2) * math.sin(deltaLat/2) + math.cos(lat1rads) * math.cos(lat2rads) * math.sin(deltaLng/2) * math.sin(deltaLng/2)
    c = 2 * math.atan2(math.sqrt(a), math.sqrt(1-a))
    d = R * c
    return d

def getDestinationLatLong(lat,lng,azimuth,distance):
    '''returns the lat an long of destination point 
    given the start lat, long, aziuth, and distance'''
    R = 6378.1 #Radius of the Earth in km
    brng = math.radians(azimuth) #Bearing is degrees converted to radians.
    d = distance/1000 #Distance m converted to km
    lat1 = math.radians(lat) #Current dd lat point converted to radians
    lon1 = math.radians(lng) #Current dd long point converted to radians
    lat2 = math.asin(math.sin(lat1) * math.cos(d/R) + math.cos(lat1)* math.sin(d/R)* math.cos(brng))
    lon2 = lon1 + math.atan2(math.sin(brng) * math.sin(d/R)* math.cos(lat1), math.cos(d/R)- math.sin(lat1)* math.sin(lat2))
    #convert back to degrees
    lat2 = math.degrees(lat2)
    lon2 = math.degrees(lon2)
    return[lat2, lon2]

def calculateBearing(lat1,lng1,lat2,lng2):
    '''calculates the azimuth in degrees from start point to end point'''
    startLat = math.radians(lat1)
    startLong = math.radians(lng1)
    endLat = math.radians(lat2)
    endLong = math.radians(lng2)
    dLong = endLong - startLong
    dPhi = math.log(math.tan(endLat/2.0+math.pi/4.0)/math.tan(startLat/2.0+math.pi/4.0))
    if abs(dLong) > math.pi:
         if dLong > 0.0:
             dLong = -(2.0 * math.pi - dLong)
         else:
             dLong = (2.0 * math.pi + dLong)
    bearing = (math.degrees(math.atan2(dLong, dPhi)) + 360.0) % 360.0;
    return bearing

def main(interval,azimuth,lat1,lng1,lat2,lng2):
    '''returns every coordinate pair inbetween two coordinate 
    pairs given the desired interval'''

    d = getPathLength(lat1,lng1,lat2,lng2)
    remainder, dist = math.modf((d / interval))
    counter = float(interval)
    coords = []
    coords.append([lat1,lng1])
    for distance in xrange(0,int(dist)):
        coord = getDestinationLatLong(lat1,lng1,azimuth,counter)
        counter = counter + float(interval)
        coords.append(coord)
    coords.append([lat2,lng2])
    return coords

if __name__ == "__main__":
    #point interval in meters
    interval = 1.0
    #direction of line in degrees
    #start point
    lat1 = 43.97076
    lng1 = 12.72543
    #end point
    lat2 = 43.969730
    lng2 = 12.728294
    azimuth = calculateBearing(lat1,lng1,lat2,lng2)
    print azimuth
    coords = main(interval,azimuth,lat1,lng1,lat2,lng2)
    print coords

I think I have fixed the bugs from the original and it should work (including change the interval). Let me know how it turns out.


I did port the Python code to php:

<?php

function parseFloat($ptString) { 
            if (strlen($ptString) == 0) { 
                    return false; 
            } 

            $pString = str_replace(" ", "", $ptString); 

            if (substr_count($pString, ",") > 1) 
                $pString = str_replace(",", "", $pString); 

            if (substr_count($pString, ".") > 1) 
                $pString = str_replace(".", "", $pString); 

            $pregResult = array(); 

            $commaset = strpos($pString,','); 
            if ($commaset === false) {$commaset = -1;} 

            $pointset = strpos($pString,'.'); 
            if ($pointset === false) {$pointset = -1;} 

            $pregResultA = array(); 
            $pregResultB = array(); 

            if ($pointset < $commaset) { 
                preg_match('#(([-]?[0-9]+(\.[0-9])?)+(,[0-9]+)?)#', $pString, $pregResultA); 
            } 
            preg_match('#(([-]?[0-9]+(,[0-9])?)+(\.[0-9]+)?)#', $pString, $pregResultB); 
            if ((isset($pregResultA[0]) && (!isset($pregResultB[0]) 
                    || strstr($preResultA[0],$pregResultB[0]) == 0 
                    || !$pointset))) { 
                $numberString = $pregResultA[0]; 
                $numberString = str_replace('.','',$numberString); 
                $numberString = str_replace(',','.',$numberString); 
            } 
            elseif (isset($pregResultB[0]) && (!isset($pregResultA[0]) 
                    || strstr($pregResultB[0],$preResultA[0]) == 0 
                    || !$commaset)) { 
                $numberString = $pregResultB[0]; 
                $numberString = str_replace(',','',$numberString); 
            } 
            else { 
                return false; 
            } 
            $result = (float)$numberString; 
            return $result; 
}   

function xrange($start, $limit, $step = 1) {
    if ($start < $limit) {
        if ($step <= 0) {
            throw new LogicException('Step must be +ve');
        }

        for ($i = $start; $i <= $limit; $i += $step) {
            yield $i;
        }
    } else {
        if ($step >= 0) {
            throw new LogicException('Step must be -ve');
        }

        for ($i = $start; $i >= $limit; $i += $step) {
            yield $i;
        }
    }
}

function modf($x) {
    $m = fmod($x, 1);
    return [$m, $x - $m];
}


function getPathLength($lat1,$lng1,$lat2,$lng2)
{
    $R = '6371000'; //# radius of earth in m
    $lat1rads = deg2rad($lat1);
    $lat2rads = deg2rad($lat2);
    $deltaLat = deg2rad(($lat2 - $lat1));
    $deltaLng = deg2rad(($lng2 - $lng1));
    $a = sin($deltaLat/2) * sin($deltaLat/2) + cos($lat1rads) * cos($lat2rads) * sin($deltaLng/2) * sin($deltaLng/2);
    $c = 2 * atan2(sqrt($a), sqrt(1 - $a));
    $d = $R * $c;
    return $d;
}

function getDestinationLatLong($lat,$lng,$azimuth,$distance){

    $R = 6378.1; //#Radius of the Earth in km
    $brng = deg2rad($azimuth); #Bearing is degrees converted to radians.
    $d = $distance / 1000; #Distance m converted to km
    $lat1 = deg2rad($lat); #Current dd lat point converted to radians
    $lon1 = deg2rad($lng); #Current dd long point converted to radians
    $lat2 = asin(sin($lat1) * cos($d/$R) + cos($lat1)* sin($d/$R)* cos($brng));
    $lon2 = $lon1 + atan2(sin($brng) * sin($d/$R)* cos($lat1), cos($d/$R)- sin($lat1)* sin($lat2));
    #convert back to degrees
    $lat2 = rad2deg($lat2);
    $lon2 = rad2deg($lon2);

    return [$lat2, $lon2];  
}

function calculateBearing($lat1,$lng1,$lat2,$lng2){
   // '''calculates the azimuth in degrees from start point to end point'''
    $startLat = deg2rad($lat1);
    $startLong = deg2rad($lng1);
    $endLat = deg2rad($lat2);
    $endLong = deg2rad($lng2);
    $dLong = $endLong - $startLong;
    $dPhi = log(tan($endLat / 2 + pi() / 4) / tan($startLat / 2 + pi() / 4));
    if (abs($dLong) > pi()) {
        if ($dLong > 0) {
            $dLong = -(2 * pi() - $dLong);
        } else {
            $dLong = 2 * pi() + $dLong;
        }
    }
    $bearing = (rad2deg(atan2($dLong, $dPhi)) + 360) % 360;
    return $bearing;
}

function main($interval, $azimuth, $lat1, $lng1, $lat2, $lng2) 
{
    $d = getPathLength($lat1, $lng1, $lat2, $lng2);
    $rapydUnpack = modf($d / $interval);
    $remainder = $rapydUnpack[0];
    $dist = $rapydUnpack[1];
    $counter = parseFloat($interval);
    $coords = [];
    array_push($coords, [ $lat1, $lng1 ]);

    $xRange = xrange(0, intval($dist));

    foreach ($xRange as $rapydIndex => $value) 
    {
    //print $value;
        $distance =$value;
        $coord = getDestinationLatLong($lat1, $lng1, $azimuth, $counter);
        $counter = $counter + parseFloat($interval);
        array_push($coords, $coord);
    }
    array_push($coords, [ $lat2, $lng2]);

    return $coords;
}

  #point interval in meters
    $interval = 10;
    #direction of line in degrees
    #start point
    $lat1 = 43.97076;
    $lng1 = 12.72543;
    #end point
    $lat2 = 43.969730;
    $lng2 = 12.728294;
    $azimuth = calculateBearing($lat1,$lng1,$lat2,$lng2);
    //print $azimuth;
    $coords = main($interval,$azimuth,$lat1,$lng1,$lat2,$lng2);
    print_r($coords);

?>