Uses MASS::sammon. The free parameter is lambda for power transformations of the observed proximities. The fitted distances power is internally fixed to 1 and the power for the weights=delta is -1.
cop_sammon(
dis,
theta = 1,
ndim = 2,
init = NULL,
weightmat = NULL,
itmaxi = 100,
...,
stressweight = 1,
cordweight = 0.5,
q = 1,
minpts = ndim + 1,
epsilon = 10,
rang = NULL,
verbose = 0,
scale = "sd",
normed = TRUE,
stresstype = "default"
)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
numeric matrix or dist object of a matrix of proximities
the theta vector of powers; this must be a scalar of the lambda transformation for the observed proximities. Defaults to 1.
number of dimensions of the target space
(optional) initial configuration
(optional) a matrix of nonnegative weights
number of iterations. default is 1000.
additional arguments to be passed to the fitting procedure
weight to be used for the fit measure; defaults to 1
weight to be used for the cordillera; defaults to 0.5
the norm of the corrdillera; defaults to 1
the minimum points to make up a cluster in OPTICS; defaults to ndim+1
the epsilon parameter of OPTICS, the neighbourhood that is checked; defaults to 10
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.
numeric value hat prints information on the fitting process; >2 is extremely verbose
should the configuration be scale adjusted
should the cordillera be normed; defaults to TRUE
which stress to report. Only takes smacofs default stress currrently.