Visio Maps: Geocoding Data with Latitude and Longitude Coordinates (254676)

SYMPTOMS

In Visio Maps, you can add addresses or locations to a map by geocoding a data file that contains either street addresses or locations with latitude and longitude coordinates. However, the latitude and longitude data must be specified in decimal format in order to be read and plotted correctly by Visio Maps.

RESOLUTION

You must convert latitude and longitude coordinates to decimal format in your external data file before geocoding the file in Visio Maps. For example, use 34.7144° but not 34,42,52 or 34°42'52". To convert latitude and longitude values from degree-minute-second (DMS) to decimal format, you can use this formula:

degrees + (minutes*1/60) + (seconds*1/3600)

If you do not convert these coordinates, the values are truncated when you geocode them. For example, 34,42,52 is read as 34. Note also that longitudinal data for the Western Hemisphere, including the United States, is always a negative value to indicate that it is west of Greenwich, England.

Tip: If your data is in a Microsoft Excel file and the latitude and longitude coordinates are formatted consistently as degrees-minutes-seconds, you can take advantage of worksheet functions to automate the conversion task. For example, the site location information in the LatDMS and LongDMS columns of the Excel table pictured below was converted to the correct decimal format (in the Latitude and Longitude columns) by using the following general formulas:

Latitude = LEFT(C2,2) + MID(C2,4,2)*1/60 + RIGHT(C2,2)*1/3600
Longitude = -1*(LEFT(E2,3) + MID(E2,5,2)*1/60 + RIGHT(E2,2)*1/3600)

Picture of page from an Excel Table showing latitude and longitude coordinates

After the latitude and longitude coordinates have been converted in your data file, in Visio Maps, on the Tools menu, click Get External Data to geocode and map the information.