Processing records using Haversine Formula in c#

Posted on 2009-07-09
Last Modified: 2013-12-17
I am new to c# and need to write a program that will process GPS postion data from a sql server database and then calculate the total distance traveled for each unit listed by date.  Each record contains a transaction id,  date/time stamp, unit id, latitude and longitude. I have bound this table to a dataset.  I also  have a class for the haversine formula which will accepts the fields LAT (A) LON (A), LAT(B), LON (B).  Where I am stuck is how to process the data from the data set (Keeping in mind that the data needs to be read one record at a time) and then loop through the records, apply the haversine formula then subtotal by unit and date.  The final step would be to insert a record into a new table that contains the Equipment ID, Date, and total miles .   Attached is the class I plan to use and sample data.    Any suggestions would be greatly appreciated.  
Question by:maximjon
LVL 15

Accepted Solution

spprivate earned 500 total points
ID: 24818604

Author Comment

ID: 25026098
This was a lot easier than I initially though.  After I setup a SQLconnection, I wrote my code to loop through the SQLdataReader one record at a time.  I simply just setup variables to retain all important info from each record (see code below)
Dim dr As SqlDataReader = myCommand.ExecuteReader()

            lngRecordCount = 1

            While dr.Read()

                If lngRecordCount > 1 Then

                    strEquipID = dr(0)

                    strInsertDate = DateValue(dr(1))

                    dblLat2 = dr(2)

                    dblLon2 = dr(3)

                    ' compare the Equipment ID and InsertDate of the two records to see if they changed.  Reset All variables and start over if they did.

                    If strPriorEquipID <> strEquipID Or strPriorInsertDate <> strInsertDate Then

                        'Write the prior equipID......

                        ' This IF statement is a temporary work around for faulty data.  Lat & Lon need to have a decimal else the haversine brings back bad data

                        If totalDistance >= 0 Then

                            myCommandWrite = New SqlCommand("INSERT INTO tblSalOutput VALUES ('" & strPriorEquipID & "', '" & strPriorInsertDate & "', " & totalDistance & ",'" & strBranch & "')", myConnectionWrite)

                            ra = myCommandWrite.ExecuteNonQuery()

                            '   MessageBox.Show("New Row Inserted" & ra)

                        End If

                        lngRecordCount = 1

                        totalDistance = 0


                        ' Now that you have lat1-lat2 & lon1-lon2, apply your formula here and write back to a serpare table

                        tmpDistance = distance(dblLat1, dblLon1, dblLat2, dblLon2)

                        totalDistance = totalDistance + tmpDistance

                    End If

                End If

                strPriorEquipID = dr(0)

                strPriorInsertDate = DateValue(dr(1))

                dblLat1 = dr(2)

                dblLon1 = dr(3)

                strBranch = dr(4)

                lngRecordCount = lngRecordCount + 1

            End While

    Public Function distance(ByVal lat1 As Double, ByVal lon1 As Double, _

                         ByVal lat2 As Double, ByVal lon2 As Double, _

                         Optional ByVal unit As Char = "M"c) As Double

        Dim theta As Double = lon1 - lon2

        Dim dist As Double = Math.Sin(deg2rad(lat1)) * Math.Sin(deg2rad(lat2)) + _

                                Math.Cos(deg2rad(lat1)) * Math.Cos(deg2rad(lat2)) * _


        dist = Math.Acos(dist)

        dist = rad2deg(dist)

        dist = dist * 60 * 1.1515

        If unit = "K" Then

            dist = dist * 1.609344

        ElseIf unit = "N" Then

            dist = dist * 0.8684

        End If

        Return dist

    End Function

    Public Function Haversine(ByVal lat1 As Double, ByVal lon1 As Double, _

                             ByVal lat2 As Double, ByVal lon2 As Double, _

                             Optional ByVal unit As Char = "M"c) As Double

        Dim R As Double = 6371 'earth radius in km

        Dim dLat As Double

        Dim dLon As Double

        Dim a As Double

        Dim c As Double

        Dim d As Double

        dLat = deg2rad(lat2 - lat1)

        dLon = deg2rad((lon2 - lon1))

        a = Math.Sin(dLat / 2) * Math.Sin(dLat / 2) + Math.Cos(deg2rad(lat1)) * _

                Math.Cos(deg2rad(lat2)) * Math.Sin(dLon / 2) * Math.Sin(dLon / 2)

        c = 2 * Math.Atan2(Math.Sqrt(a), Math.Sqrt(1 - a))

        d = R * c

        Select Case unit.ToString.ToUpper

            Case "M"c

                d = d * 0.62137119

            Case "N"c

                d = d * 0.5399568

        End Select

        Return d

    End Function

    Private Function deg2rad(ByVal deg As Double) As Double

        Return (deg * Math.PI / 180.0)

    End Function

    Private Function rad2deg(ByVal rad As Double) As Double

        Return rad / Math.PI * 180.0

    End Function

Open in new window


Featured Post

3 Use Cases for Connected Systems

Our Dev teams are like yours. They’re continually cranking out code for new features/bugs fixes, testing, deploying, testing some more, responding to production monitoring events and more. It’s complex. So, we thought you’d like to see what’s working for us.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Everyone has problem when going to load data into Data warehouse (EDW). They all need to confirm that data quality is good but they don't no how to proceed. Microsoft has provided new task within SSIS 2008 called "Data Profiler Task". It solve th…
A long time ago (May 2011), I have written an article showing you how to create a DLL using Visual Studio 2005 to be hosted in SQL Server 2005. That was valid at that time and it is still valid if you are still using these versions. You can still re…
Via a live example, show how to extract information from SQL Server on Database, Connection and Server properties
Viewers will learn how the fundamental information of how to create a table.

932 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

13 Experts available now in Live!

Get 1:1 Help Now