Solved

Processing records using Haversine Formula in c#

Posted on 2009-07-09
3
709 Views
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.  
Haversine---Copy.txt
Data.txt
0
Comment
Question by:maximjon
3 Comments
 
LVL 15

Accepted Solution

by:
spprivate earned 500 total points
ID: 24818604
0
 

Author Comment

by:maximjon
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
                    Else
                        ' 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)) * _
                                Math.Cos(deg2rad(theta))
        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

0

Featured Post

Free Tool: SSL Checker

Scans your site and returns information about your SSL implementation and certificate. Helpful for debugging and validating your SSL configuration.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

Question has a verified solution.

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

This article shows gives you an overview on SQL Server 2016 row level security. You will also get to know the usages of row-level-security and how it works
This article aims to explain the working of CircularLogArchiver. This tool was designed to solve the buildup of log file in cases where systems do not support circular logging or where circular logging is not enabled
Via a live example, show how to set up a backup for SQL Server using a Maintenance Plan and how to schedule the job into SQL Server Agent.
Viewers will learn how to use the UPDATE and DELETE statements to change or remove existing data from their tables. Make a table: Update a specific column given a specific row using the UPDATE statement: Remove a set of values using the DELETE s…

762 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