Generates an initial configuration of startn
points from
dataset x
for the fixmahal
fixed point iteration.
Thought only for use within fixmahal
.
mahalconf(x, no, startn, covall, plot)
numerical matrix. Rows are points, columns are variables.
integer between 1 and nrow(x)
. Number of the first
point of the configuration.
integer between 1 and nrow(x)
.
covariance matrix for the computation of the first Mahalanobis distances.
a string. If equal to "start"
or "both"
,the
first two variables and the first ncol(x)+1
points are plotted.
A logical vector of length nrow(x)
.
mahalconf
first chooses the \(p\) (number of variables)
nearest points to point no. no
in terms of the Mahalanobis
distance w.r.t. covall
, so that there are \(p+1\) points.
In every further step, the covariance
matrix of the current configuration is computed and the nearest point
in terms of the new Mahalanobis distance is
added. solvecov
is used to invert singular covariance
matrices.
# NOT RUN { set.seed(4634) face <- rFace(600,dMoNo=2,dNoEy=0,p=2) mahalconf(face,no=200,startn=20,covall=cov(face),plot="start") # }