cop_elastic {cops}

PCOPS versions of elastic scaling models (via smacofSym)

Description

The free parameter is lambda for power transformations the observed proximities. The fitted distances power is internally fixed to 1 and the power for the weights=delta is -2. Allows for a weight matrix because of smacof.

Usage

cop_elastic(
  dis,
  theta = 1,
  ndim = 2,
  weightmat = 1,
  init = NULL,
  itmaxi = 1000,
  ...,
  stressweight = 1,
  cordweight = 0.5,
  q = 1,
  minpts = ndim + 1,
  epsilon = 10,
  rang = NULL,
  verbose = 0,
  normed = TRUE,
  scale = "sd",
  stresstype = "default"
)

Arguments

dis

numeric matrix or dist object of a matrix of proximities

theta

the theta vector of powers; this must be a scalar of the lambda transformation for the observed proximities. Defaults to 1.

ndim

number of dimensions of the target space

weightmat

(optional) a matrix of nonnegative weights (NOT the elscal weights)

init

(optional) initial configuration

itmaxi

number of iterations. default is 1000.

...

additional arguments to be passed to the fitting procedure

stressweight

weight to be used for the fit measure; defaults to 1

cordweight

weight to be used for the cordillera; defaults to 0.5

q

the norm of the corrdillera; defaults to 1

minpts

the minimum points to make up a cluster in OPTICS; defaults to ndim+1

epsilon

the epsilon parameter of OPTICS, the neighbourhood that is checked; defaults to 10

rang

range of the distances (min distance minus max distance). If NULL (default) the cordillera will be normed to each configuration's maximum distance, so an absolute value of goodness-of-clusteredness.

verbose

numeric value hat prints information on the fitting process; >2 is extremely verbose

normed

should the cordillera be normed; defaults to TRUE

scale

should the configuration be scale adjusted

stresstype

which stress to report. Only takes smacofs default stress currrently.

Value

A list with the components

• stress: the stress

• stress.m: default normalized stress

• copstress: the weighted loss value

• OC: the Optics cordillera value

• parameters: the parameters used for fitting (kappa, lambda)

• fit: the returned object of the fitting procedure

• cordillera: the cordillera object