vb.net - calculate the distance using longitude and latitude in vb using array -

i writing windows application find distance using latitude , longitude . have more 100 numbers of value in array , got formula find distance

dim theta double = lon1 - lon2 dim dist double = math.sin(deg2rad(lat1)) * math.sin(deg2rad(lat2)) + math.cos(deg2rad(lat1)) * math.cos(deg2rad(lat2)) * math.cos(deg2rad(theta)) dist = math.acos(dist) dist = rad2deg(dist) dist = dist * 60 * 1.1515 dist = dist * 1.609344    

i have arrange value lat1,lat2,lon1,lon2 ? suggestion how can arrange array pass value ?

first, decide on container store each coordinate, perhaps structure or class.

public class coordinate     public latitude double     public longitude double      public sub new(byval lon double, byval lat double)         latitude = lat         longitude = lon     end sub end class 

then you'll need collection store of coordinates, maybe list or dictionary (if want reference them index).

public coordinates as new dictionary(of integer, coordinate) 

then assignments,

coordinates.add(1, new coordinate(654.321, 123.456)) coordinates.add(2, new coordinate(321.654, 456.123)) 

you can build function accept custom container input.

public function calcdistance(byval coord1 coordinate, byval coord2 coordinate) double     dim lon1 double = coord1.longitude     dim lat1 double = coord1.latitude     dim lon2 double = coord2.longitude     dim lat2 double = coord2.latitude     'do math!     return dist end function 

finally, call function, pass values, , magic happens!

dim distancebetween double = calcdistance(coordinates(1), coordinates(2)) 

update: user control seems terrible place store data, i'm reluctant provide this, since it's second attempt @ posting question, here's simple way use you've got.

public function calcdistance(byval lon1 double, byval lat1 double, byval lon2 double, byval lat2 double) double     'do math!     return dist end function  dim distancebetween double = calcdistance(cdbl(listbox1.items(0).value), cdbl(listbox2.items(0).value), cdbl(listbox1.items(1).value), cdbl(listbox2.items(1).value))