Editing with Neighbor Graphs
Description
Similaritybased filter for removing label noise from a dataset as a preprocessing step of classification. For more information, see 'Details' and 'References' sections.
Usage
1 2 3 4 5 
Arguments
formula 
A formula describing the classification variable and the attributes to be used. 
data, x 
Data frame containing the tranining dataset to be filtered. 
... 
Optional parameters to be passed to other methods. 
graph 
Character indicating the type of graph to be constructed. It can be chosen between 'GG' (Gabriel Graph) and 'RNG' (Relative Neighborhood Graph). See 'References' for more details on both graphs. 
classColumn 
positive integer indicating the column which contains the (factor of) classes. By default, the last column is considered. 
Details
ENG
builds a neighborhood graph which can be either Gabriel Graph (GG) or
Relative Neighborhood Graph (RNG) [S\'anchez et al., 1997]. Then, an
instance is considered as 'potentially noisy' if most of its neighbors have a different class. To decide whether such
an instance 'X' is removed, let S be the subset given by 'X' together with its neighbors from the same class.
Compute the majority class 'C' among the neighbors of examples in S, and remove 'X' if its class is not 'C'.
Value
An object of class filter
, which is a list with seven components:

cleanData
is a data frame containing the filtered dataset. 
remIdx
is a vector of integers indicating the indexes for removed instances (i.e. their row number with respect to the original data frame). 
repIdx
is a vector of integers indicating the indexes for repaired/relabelled instances (i.e. their row number with respect to the original data frame). 
repLab
is a factor containing the new labels for repaired instances. 
parameters
is a list containing the argument values. 
call
contains the original call to the filter. 
extraInf
is a character that includes additional interesting information not covered by previous items.
References
S\'anchez J. S., Pla F., Ferri F. J. (1997): Prototype selection for the nearest neighbour rule through proximity graphs. Pattern Recognition Letters, 18(6), 507513.
Examples
1 2 3 4 5 6 7 8 9  # The example is not run because the graph construction is quite timeconsuming.
## Not run:
data(iris)
trainData < iris[c(1:20,51:70,101:120),]
out < ENG(Species~Petal.Length + Petal.Width, data = trainData, graph = "RNG")
print(out)
identical(out$cleanData,trainData[setdiff(1:nrow(trainData),out$remIdx),])
## End(Not run)
