do.klde {Rdimtools} | R Documentation |
Kernel Local Discriminant Embedding
Description
Kernel Local Discriminant Embedding (KLDE) is a variant of Local Discriminant Embedding in that it aims to preserve inter- and intra-class neighborhood information in a nonlinear manner using kernel trick. Note that the combination of kernel matrix and its eigendecomposition often suffers from lacking numerical rank. For such case, our algorithm returns a warning message and algorithm stops working any further due to its innate limitations of constructing weight matrix.
Usage
do.klde(
X,
label,
ndim = 2,
t = 1,
numk = max(ceiling(nrow(X)/10), 2),
preprocess = c("center", "scale", "cscale", "decorrelate", "whiten"),
ktype = c("gaussian", 1),
kcentering = TRUE
)
Arguments
X |
an |
label |
a length- |
ndim |
an integer-valued target dimension. |
t |
kernel bandwidth in |
numk |
the number of neighboring points for k-nn graph construction. |
preprocess |
an additional option for preprocessing the data.
Default is "center". See also |
ktype |
a vector containing name of a kernel and corresponding parameters. See also |
kcentering |
a logical; |
Value
a named list containing
- Y
an
(n\times ndim)
matrix whose rows are embedded observations.- trfinfo
a list containing information for out-of-sample prediction.
Author(s)
Kisung You
References
Hwann-Tzong Chen, Huang-Wei Chang, Tyng-Luh Liu (2005). “Local Discriminant Embedding and Its Variants.” In 2005 IEEE Computer Society Conference on Computer Vision and Pattern Recognition, volume 2, 846–853.
Examples
## generate data of 2 types with clear difference
set.seed(100)
diff = 25
dt1 = aux.gensamples(n=50)-diff;
dt2 = aux.gensamples(n=50)+diff;
## merge the data and create a label correspondingly
X = rbind(dt1,dt2)
label = rep(1:2, each=50)
## try different neighborhood size
out1 <- do.klde(X, label, numk=5)
out2 <- do.klde(X, label, numk=10)
out3 <- do.klde(X, label, numk=20)
## visualize
opar = par(no.readonly=TRUE)
par(mfrow=c(1,3))
plot(out1$Y, col=label, pch=19, main="k=5")
plot(out2$Y, col=label, pch=19, main="k=10")
plot(out3$Y, col=label, pch=19, main="k=20")
par(opar)