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Neighborhood database

Description

1. A neighborhood database is a collection of geo-referenced items and their neighbors.
2. A geo-referenced item j is said to be a neighbor of another geo-referenced item i if the distance between them is no more than the user-specified maximum distance threshold value. That is, if distance(i,j) <=maximumDistance, we say j is a neighbor of i.
3. A sample neighborhood database generated from the set of geo-referenced items, I={a,b,c,d,e,f}, is shown in below table:

Item	Neighbors
Point(0 0)	Point(1 0) Point(0 1)
Point(1 0)	Point(0 0) Point(0 1) Point(2 0)
…	…

Rules to create a neighborhood database

1. Every row in the neighborhood file must contain only geo-referenced items.
2. First item in a row is the main geo-referenced item. Remaining items in a row represent the neighbors of main item.
3. All items in a row are seperated with a seperator, say tab space.
4. Note: Every item must repeat only once in a row.

Format to create a neighborhood database

item<seperator>NeighboringItem1<seperator>NeighboringItem2<seperator>...

An example

item1   item3   item4   item10  
item2   item3   item5   item11  ...
...

Procedure to generate neighborhood file

Step 1: Import the program

from PAMI.extras.neighbours import  createNeighborhoodFileUsingEuclideanDistance as alg

Step2: Specify the parameters

inputLocationFile='geoReferencedInputFile.csv'  #name of the input file 
outputNeighborhoodFile='neighborhoodFile.csv'       #name of the output file
maximumDistance=10      #specify your own value
seperator='\t'      #default seperator.

Step 3: Call the program

alg.createNeighborhoodFileUsingEuclideanDistance(inputLocationFile,outputNeighborhoodFile,maximumDistance,seperator)