METHOD FOR CONVERTING POINT ADDRESS DATA

1 . A method for converting a database of point address data into a database of address range data using a computer, wherein each point address comprises an address number, a street name and a geographical location, the method comprising:

assigning each point address to a chain based upon its street name;

ordering the point addresses in each chain according to their geographical location;

determining the direction and range of the road numbers in at least part of at least one chain; and

storing the direction and range data as address range data.

2 . The method of claim 1 , further comprising:

finding the junctions between chains by noting points where chains meet; and

dividing at least one chain into intervals, each interval being defined as a section of chain between two subsequent junctions,

before determining the direction and range of the address numbers in at least part of at least one interval and storing the direction and range data as address range data.

3 . The method of claim 1 , further comprising:

dividing at least one chain or interval into sides, each side of a chain or interval corresponding to a side of the street,

before determining the direction and range of the address numbers in at least part of at least one side and storing the direction and range data as address range data.

4 . The method of claim 3 , further comprising:

determining the parity of the address numbers in at least part of at least one side.

5 . The method of claim 1 , further comprising:

checking and correcting the point address data,

before determining the direction and range of the address numbers in at least part of at least one side and storing the direction and range data as address range data.

6 . The method of claim 5 , wherein the point address data is checked by analysing the address numbers, street names and geographical locations to ensure that they comply with an expected format.

7 . The method of claim 5 , wherein the point address data is checked by determining the prevailing direction of count of address numbers for at least part of at least one chain and

the point address data is corrected by swapping, deleting or replacing any address numbers which are out of position given the prevailing direction of count.

8 . The method of claim 5 , wherein the point address data is checked by determining the prevailing parity of address numbers for at least part of at least one chain and

the point address data is corrected by swapping, deleting or replacing any address numbers which are out of position given the prevailing parity.

9 . The method of claim 5 , wherein the point address data is checked by searching for gaps in the address numbers of at least part of at least one chain and

the point address data is corrected by creating new address numbers in that gap.

10 . The method of claim 1 , further comprising checking and correcting the address range data.

11 . A method for checking a first set of address range data in a database, the method comprising:

acquiring point address data for the area to be checked;

converting the point address data into a second set of address range data using a method according to claim 1 ; and

checking the first set of address range data against a second set of address range data.

12 . A method for compressing point address data, the method comprising converting the point address data into a set of address range data using a method according to claim 1 .

13 . A computer program product directly loadable into the internal memory of a digital computer, comprising computer software code for performing a method as claimed in claim 1 .