Embed Size (px)
Citation preview
Nearest Neighbor
An Explanation of Nearest Neighbor and how to use it to get to
know your data in Matlab
Match Making for Soda Lovers
Sw
eetness
Sw
eetness
Carbonation
Sw
eetness
Carbonation
Price
Sw
eetness
Carbonation
Price
Acidity
Sw
eetness
Carbonation
Price
Acidity
Caffeination
Sw
eetness
Carbonation
Price
Acidity
Caffeination
Etc.
Sw
eetness
Carbonation
Price
Acidity
Caffeination
Etc.
Etc.
Sw
eetness
Carbonation
Price
Acidity
Caffeination
Etc.
Etc.
Etc.
Sweetness
Carbonation
Price
Soda ID Sweetness Carbonation Price
Soda 1 3.5 4.3 $1.00
Soda 2 5.1 4.1 $1.50
Soda 3 4.2 2.2 $2.00
Soda 4 3.1 4.2 $0.75
Soda 5 6 3.0 $0.50
Sweetness
Carbonation
Price
xlsread(filename)csvread(filename)
Sweetness Carbonation Price
3.5 4.3 $1.00
5.1 4.1 $1.50
4.2 2.2 $2.00
3.1 4.2 $0.75
6 3.0 $0.50
Soda Brand
Soda 1
Soda 2
Soda 3
Soda 4
Soda 5
[SODAS, BRANDS] = xlsread(filename)
*
***
**
*
*
**
***
***
**
*
*
**
***
***
**
*
*
**
***
***
**
*
*
**
***
The Basic Math
Differencein Sweetness
Differencein Carbonation
Differencein Price
Sweetness
Carbona
tion
a
b
A^2 + b^2 = c^3
Distance:(in lots of dimensions)
MatlabdsearchnN-Dimensional nearest point search
Syntaxk = dsearchn(SODAS,IDEALS)
rangesearchFind all neighbors specified distance using KDTreeSearcher object
Syntax[idx,D]= rangesearch(SODATREE,IDEALS,r)
MatlabdsearchnN-Dimensional nearest point search
Syntaxk = dsearchn(SODAS,IDEALS)
knnsearchFind k-nearest neighbors using data
Syntax[IDX,D] = knnsearch(SODATREE,IDEALS,r)
For single nearestpoint
For More Neighbors(requires a tree)
Easy One Match SearchdsearchnN-Dimensional nearest point search
SyntaxI = dsearchn(SODAS,IDEALS)
Harder Multi Match SearchBuilding a Tree
Sweetness Carbonation Price
3.5 4.3 $1.00
5.1 4.1 $1.50
4.2 2.2 $2.00
3.1 4.2 $0.75
6 3.0 $0.50
SODATREE = kdtreesearcher(SODAS,'distance')
All the Sodas
Sweetness Carbonation Price
3.5 4.3 $1.00
5.1 4.1 $1.50
4.2 2.2 $2.00
rangesearchFind all neighbors specified distance using KDTreeSearcher object
Syntax[I,D]= rangesearch(SODATREE,IDEALS,r)
**r
Harder Multi Match SearchGetting neighbors
Ideal Sodas
