Tuesday - April 10, 2007

What's New at MP2K Magazine - Articles

Welcome to another issue of the MP2Kmag Update. This issue includes six new articles, each with downloadable sample code contributed by readers in the past few months. In upcoming issues we will focus on MapPoint / Virtual Earth news and share highlights from www.mapforums.com.

MP2K Magazine is your source for independent news and information about MapPoint and Virtual Earth technologies and is home to the popular web forum for MapPoint users and developers. In this issue we also also feature another tutorial on Automating MapPoint with Excel VBA and announce the re-launching of the MapVisitors.com application.

This Issue's Contents at a Glance
 - features: MapPoint Programming Tutorial: Drawing Circles Around a List of Addresses, Relaunching MapVisitors.com
 - Using Virtual Earth to Write a Vista Gadget That Tracks the International Space Station 
 - Determing Whether A Point Is Located Inside Polygon
 - Using Virtual Earth in a Vista Gadget 
 - An API to Control MapPoint 2006 GPS Features - Part I of II
 - Using MapPoint and Excel for Supply Chain Management 
 - Creating Geocoding Exceptions for MapPoint Web Service Applications

Happy Mapping and please forward this newsletter to anyone who would be interested!

Automating MapPoint with Excel VBA - Tutorial 5

In this installment of the tutorial series on programming MapPoint with Excel we should how to loop over a series of addresses and plot pushpins and draw radius circles around each location. Earlier tutorials can be found here 1, 2, 3, and 4.

To get started with this tutorial, download the spreadsheet with VBA code. The code works with MapPoint North America and the sample data is for the North American version, but it can be easily modified for MapPoint Europe. Let me know if you would like help with this and I will post it in the discussion area for the tutorials.

The main portion of the code is a loop. The program looks for a list of addresses on the spreadsheet stops when it finds the first blank line. Further comments are found in the code below.

  szAddress = Cells(nCurrentRow, 3)
  Do While (szAddress <> 0)  'stop when it reaches a blank line.

    'read line from spreadsheet and assign to variables
    szName = Cells(nCurrentRow, 2)
    szCity = Cells(nCurrentRow, 4)
    szState = Cells(nCurrentRow, 5)
    szZip = Cells(nCurrentRow, 6)
    nRadius = Cells(nCurrentRow, 7) 'column G

    'find the address and add a pushpin to the map
    Set objFindResults = objMap.FindAddressResults(szAddress, szCity, , szState, szZip)
    Set objLoc = objFindResults(1)
    Set objPushpin = objMap.AddPushpin(objLoc, szName)

    'draws circle based on radius in column G
    objMap.Shapes.AddShape geoShapeRadius, objLoc, nRadius, nRadius

    'pop up pushpin name
    objPushpin.BalloonState = geoDisplayName
   
    nCurrentRow = nCurrentRow + 1
    szAddress = Cells(nCurrentRow, 3)
   
  Loop

If you have any questions, suggestions, or enhancements you would like to share please post in the MapPoint / Excel VBA discussion thread. Keep an eye out for a continuation of this series in future issues.

MapVisitors.com Virtual Earth Webmaster Tool Mashup

The MapVisitors application was first mentioned in this newsletter back in 2005 has now been moved to its own web site at www.mapvisitors.com. MapVisitors is a free tool for web sites to generate a worldwide map of their visitors. Additional features to be added soon include a color-coded map at low resolutions to more clearly depict concentrations of visitors, ability to use custom graphics, improving the layout and look of the map, and more -- send us your feature requests. This is the html code to paste into your web site layout --

<a href='http://www.mapvisitors.com/' title='Map of Visitors'><img src='http://www.mapvisitors.com/m.png' alt='IP Map' style='border:0'></a>

If you would like a custom graphic that uses a different button or image that better fits into your web site design, send it to me and I will get it ready right away and provide you with the new html code. Inquire about a custom implementation of this tool for your web site.

This is the second of a two article series about writing Vista Gadgets that use Virtual Earth. The first article ("Using Virtual Earth in a Vista Gadget") showed you how to write a Vista Gadget that showed a simple interactive map using Virtual Earth. This second article extends the gadget into something more useful: A Tracker for the International Space Station (ISS)

"At start up, the gadget automatically downloads the latest orbital parameters from the AmSat website. The map is updated every half second with the ISS’s latest position. The position is tracked with a pushpin shaped like the ISS. The map automatically pans to keep the ISS centered in the map. The user may zoom in or out using "+" and "-" buttons. A "Refresh" button allows the orbital parameters to be refreshed from AmSat. These orbital parameters should only be refreshed every few days -- you do not need to do this if you restart Vista (and hence the gadget) on a daily basis.

Instead of two files, the gadget now contains ten files. One of these is an image: ISS_pin.gif stores the image of the ISS pushpin. The remaining extra files (global.js, graphic_clock.js, math.js, sgp4sdp4.js, time.js, utils.js, view.js ) are all JavaScript files used to calculate the orbit of the ISS. These are based on the orbit calculation routines available from http://www.movingsatellites.com."

   Full article text Discuss this story  Download code

Wilfried Mestdagh wrote this article on determing whether a vehicle is located inside or outside a convex polygon. "Simplify the polygon by make triangles from it one by one, until we have a triangle where the point is inside. At the end we only have to verify if the point is in the last triangle."

"This article explains a method to calculate if a position is in or outside a convex polygon. It does not make use of floating point numbers to optimize for speed as much as possible. To transform Latitude / Longitude pairs into X/Y coordiantes, just multiply them with a given factor, for example 100000. 1/100000 of a degree gives precision of around 1 meter which is already better than any GPS receiver. 

To make the calculations easy we will reduce the polygon to triangles by replacing each time two successive sides by a new one, provided that the triangle formed by the two polygon sides and the new side does not contain the point."

   Full article text Discuss this story  Download code

Programming MapPoint in .NET Chandu Thota's New Book from O'Reilly Press Free USPS Priority Shipping - $48 The first and only book in print on programming MapPoint technologies. The book includes sections on MapPoint 2004, the MapPoint Web Service, MapPoint Location Server, and Virtual Earth. The books is 354 pages chock full of programming examples and map screenshots. For example, the book spends 40 pages discussing in depth the various Data Map styles in MapPoint 2004, dissects the DisplayDataMap method in detail, and has a number of examples of importing data from various sources. There are over 100 pages on the MapPoint Web Service including sections on the Find, Route, and Render API's. Inquire about international shipping and multiple copy discounts. Take your MapPoint programming to the next level! Order Your Copy Today - Free Shipping!