Rijnsent
Well-known Member
- Joined
- Oct 17, 2005
- Messages
- 1,416
- Office Version
- 365
- Platform
- Windows
I'm trying to build some geographical classes in VBA. Am rather experienced in VBA, but do get stuck here. What I would like to do is set a geographical box, based on 2 coordinates (e.g. North Eastern point and South Western point). The coordinate-class is set up and works fine (named latLng), but I can't figure out how to set up the latLngBounds class. Can anyone here help me out?
Below are:
The working code for latLng:
And the trouble maker (effort so far):
Below are:
- my VBA test script
- the working latLng class
- the trouble maker latLngBounds class
VBA Code:
'TESTSCRIPT:
Sub TestBox()
Dim CoordSW As New latLng
CoordSW.lat = 52.067267
CoordSW.lon = 5.1114603
Dim CoordNE As New latLng
CoordNE.lat = 52.074799
CoordNE.lon = 5.1285214
Debug.Print CoordSW.toString
Debug.Print CoordSW.distanceTo(CoordNE)
Dim TotBox As New latLngBounds '? probably not the right way?
'Set TotBox.latLngBounds(CoordSW,CoordNE) '? same here?
End Sub
The working code for latLng:
VBA Code:
' CLASS MODULE CODE for latLng
' following logic from https://leafletjs.com/reference-1.6.0.html#latlngbounds
' https://excelmacromastery.com/vba-class-modules/
'x = lon - East/West
'y = lat - North/South
' Member variable
Private clat As Double
Private clon As Double
' Properties
Property Get lat() As Double
lat = clat
End Property
Property Let lat(value As Double)
clat = value
End Property
Property Get lon() As Double
lon = clon
End Property
Property Let lon(value As Double)
clon = value
End Property
' Event - triggered when class created
Private Sub Class_Initialize()
clat = 0
clon = 0
End Sub
Public Function toString() As String
'toString() String Returns a string representation of the point (for debugging purposes).
'e.g. LatLng(51.504789, 5.046692)
toString = "LatLng(" & Trim(Str(clat)) & "," & Str(clon) & ")"
End Function
Public Function distanceTo(latLngIn As latLng) As Double
'distanceTo(<LatLng> otherLatLng) Number Returns the distance (in meters) to the given LatLng calculated using the Spherical Law of Cosines.
'http://www.cpearson.com/excel/LatLong.aspx
Dim Delta As Double
Dim C_PI As Double
C_PI = 4 * Atn(1)
Dim C_RADIUS_EARTH_KM As Double
C_RADIUS_EARTH_KM = 6370.97327862
' convert to radians: radians = (degrees/180) * PI
Dim Lat1 As Double
Dim Lat2 As Double
Dim Long1 As Double
Dim Long2 As Double
Lat1 = (latLngIn.lat / 180) * C_PI
Lat2 = (clat / 180) * C_PI
Long1 = (latLngIn.lon / 180) * C_PI
Long2 = (clon / 180) * C_PI
Delta = ((2 * ArcSin(Sqr((Sin((Lat1 - Lat2) / 2) ^ 2) + Cos(Lat1) * Cos(Lat2) * (Sin((Long1 - Long2) / 2) ^ 2)))))
distanceTo = 1000 * C_RADIUS_EARTH_KM * Delta
End Function
Private Function ArcSin(X As Double) As Double
' VBA doesn't have an ArcSin function. Improvise.
ArcSin = Atn(X / Sqr(-X * X + 1))
End Function
And the trouble maker (effort so far):
VBA Code:
' CLASS MODULE CODE for latLngBounds
' following logic from https://leafletjs.com/reference-1.6.0.html#latlngbounds
' https://excelmacromastery.com/vba-class-modules/
' Member variable
Private clatmax As Double
Private clonmax As Double
Private clatmin As Double
Private clonmin As Double
' Properties
Property Set latLngBounds(coord1 As latLng, coord2 As latLng)
'? Is this the right way? Maybe should be a Let?
If coord1.lat > coord2.lat Then
clatmax = coord1.lat
clatmin = coord2.lat
Else
clatmax = coord2.lat
clatmin = coord1.lat
End If
If coord1.lon > coord2.lon Then
clonmax = coord1.lon
clonmin = coord2.lon
Else
clonmax = coord2.lon
clonmin = coord1.lon
End If
End Property
' Event - triggered when class created
Private Sub Class_Initialize()
clatmin = 0
clatmax = 0
clonmin = 0
clonmax = 0
End Sub
Public Function getCenter() As latLng
'getCenter() LatLng
'Returns the center point of the bounds.
Dim CoordCenter As New latLng
CoordCenter.lat = (clatmax + clatmin) / 2
CoordCenter.lon = (clonmax + clonmin) / 2
getCenter = CoordCenter
End Function