Given that MapInfo Pro has identified a street, it has to deal with street numbers. MapInfo Pro stores address ranges with each street segment. MapInfo Pro takes the street number from the target address and compares it to the ranges for each segment in the source table. For example, assume that we are trying to match "343 LaSalle St". MapInfo stores the beginning and ending address for each segment, differentiating between left and right sides of the street, as follows:
Name | FromLeft | ToLeft | FromRight | ToRight |
---|---|---|---|---|
LaSalle St |
269 |
331 |
268 |
330 |
LaSalle St |
333 |
375 |
332 |
374 |
LaSalle St |
377 |
401 |
376 |
400 |
To match "343 LaSalle St" MapInfo Pro would scan the address ranges until it finds the one where "343" goes. Since 343 is between 333 and 375, the applications locates this address on that street segment (the middle one in the table). Once MapInfo Pro has matched an address number to a street segment it moves to the next row. When it fails to match a target street number to an address range on the appropriate street it:
- In Automatic mode, it moves to the next row
- In Interactive mode, it presents you with the closest matches and you pick the best match. MapInfo Pro then moves on to the next row.
At this point MapInfo Pro has done the best it can at locating address numbers. Note that one of the options (on the Geocode Options dialog box) is to automatically pick the closest address range in cases where there is no exact match-Use The Closest Address Number. For example, you might have "412" as an address number, but no range which includes that number. However, there is a range which goes from 346 to 400. Since that is the range closest to 412, that is where MapInfo Pro will geocode 412 if you have chosen this particular option. The next step is to deal with addresses which have been located on more than one street.