Rdimtools (version 0.4.1)

do.fastmap: FastMap

Description

do.fastmap is an implementation of FastMap algorithm. Though it shares similarities with MDS, it is innately a nonlinear method that iteratively updates the projection information using pairwise distance information.

Usage

do.fastmap(X, ndim = 2, preprocess = c("null", "center", "scale",
  "cscale", "whiten", "decorrelate"))

Arguments

X

an \((n\times p)\) matrix or data frame whose rows are observations and columns represent independent variables.

ndim

an integer-valued target dimension.

preprocess

an additional option for preprocessing the data. Default is "null". See also aux.preprocess for more details.

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.

References

faloutsos_fastmap:_1995Rdimtools

Examples

# NOT RUN {
## load iris data
data(iris)
X <- as.matrix(iris[,1:4])

## let's compare with other methods
out1 <- do.pca(X, ndim=2)      # PCA
out2 <- do.mds(X, ndim=2)      # Classical MDS
out3 <- do.fastmap(X, ndim=2)  # FastMap

## visualize
par(mfrow=c(1,3))
plot(out1$Y[,1], out1$Y[,2], main="PCA")
plot(out2$Y[,1], out2$Y[,2], main="MDS")
plot(out3$Y[,1], out3$Y[,2], main="FastMap")
# }
# NOT RUN {
# }