Given a table
> $cat data.csv
>
> ID,State,City,Price,Number,Flag
> 1,CA,A,100,1000,0
> 2,CA,A,96,1010,1
> 3,CA,A,195,1010,1
> 4,NY,B,124,2000,0
> 5,NY,B,128,2001,1
> 6,NY,C,24,30000,0
> 7,NY,C,27,30100,1
> 8,NY,C,29,30200,0
> 9,NY,C,39,33000,1
Expected Result:
ID0, ID1
1,2
4,5
6,7
8,7
for each ID with Flag=0 above, we want to find another ID from Flag=1, with
the same "State" and "City", and the nearest Price and Number normalized by
the corresponding values of that ID with Flag=0.
For example, ID = 1 and ID=2, has the same State and City, but different
FLAG.
After normalized the Price and Number (Price divided by 100, Number divided
by 1000), the distance between ID=1 and ID=2 is defined as :
abs(100/100 - 96/100) + abs(1000/1000 - 1010/1000) = 0.04 + 0.01 = 0.05
What's the best way to find such nearest neighbor? Any valuable tips will
be greatly appreciated!
