basis_onpp: The basis of Orthogonal Neighborhood Preserving Projection (OLPP)
Description
Orthogonal Neighborhood Preserving Projection (ONPP) is an unsupervised
linear dimension reduction method. It constructs a weighted data graph from
LLE method. Also, it develops LPP method by preserving the structure of local
neighborhoods. For the more details on type see
Rdimtools::aux.graphnbd().
Usage
basis_onpp(data, d = 2, type = c("knn", sqrt(nrow(data))))
Arguments
data
Numeric matrix or data.frame of the observations, coerced to matrix.
d
Number of dimensions in the projection space.
type
A vector specifying the neighborhood graph construction.
Expects; c("knn", k), c("enn", radius), or c("proportion",ratio).
Defaults to c("knn", sqrt(nrow(data))), nearest neighbors equal to the
square root of observations.
Value
Orthogonal matrix basis that distinguishes the levels of class
based on local and non-local variation as weighted against the neighborhood
graph.
References
He X (2005). Locality Preserving Projections. PhD Thesis,
University of Chicago, Chicago, IL, USA.