Pitney Bowes MapXtreme - Manual (Page 336)

Chapter 18: Geocoding
Using Constraints for Accurate Geocoding
MapXtreme v7.1 343 Developer Guide
Postal Code Geocoding
Postal code centroids represent the centre of a postal code region. Being able to locate these
centroids on a map lets you perform demographic analysis to find market regions to target for
advertising or direct mail. For postal code level geocoding, use the Address class specifying only the
PrimaryPostalCode information.
Gazetteer Type Geocoding
As part of the geocoding client, you can perform a world, country, or city geocode operation that can
find the position of a partial address containing only the city, state, or a place name. The following
operations are supported:
• Search, based on country, country subdivision, city, city subdivision, landmark, or airport to
return the position.
• The pattern search capability supports a wildcard character (*) as a search value in one or more
fields to return all available values for that particular field.
Batch Geocoding
Batch geocoding is supported using the IGeocodeClient.BatchRequests property. This property sets
the number of addresses that will be sent to the server for a single operation. The defaults number of
addresses is 25. The BatchRequest property must be greater than 0 and less than 500. When
submitting addresses to the IGeocodeClient.Geocode() method, you may exceed the number
specified in the BatchRequest property. If this occurs, the geocode operation containing these
addresses will be broken down into multiple operations, where each operation contains no more
than the number specified in the BatchRequest property.
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A small number for BatchRequst (e.g., 2) will slow performance. A high number for
BatchRequest (e.g., 500) may result in memory issues. The performance of batch geocoding
is dependant on system configuration.
Using Constraints for Accurate Geocoding
The geocode client allows you to set the match restrictions, fallback, and multiple match settings
when geocoding input addresses using the GeocodeConstraints class. Here you set the preferences
to be as strict or relaxed as you need. The settings that give you the best compromise among match
rate, accuracy, and performance, are:
• Require an exact match for house number and street name.
• Do not fall back to postal code centroid.
• Return close matches only.
The strictest matching conditions require an exact match on house number, street name, postal
code and no fallback to postal code centroids. The server or service, in essence, looks for an exact
street address match within the postal code named in your input address.