| smacofx {smacofx} | R Documentation |
smacofx: Flexible multidimensional scaling methods and SMACOF extensions
Description
Flexible multidimensional scaling (MDS) methods centered around the Majorization algorithm. The package contains various functions, wrappers, methods and classes for fitting, plotting and displaying a large number of different flexible MDS models such as Torgerson scaling, ratio, interval and nonmetric MDS with majorization, Sammon mapping with ratio and interval optimal scaling, multiscale MDS with ratio and interval optimal scaling, Alscal (s-stress) MDS with ratio and interval optimal scaling, elastic scaling with ratio and interval optimal scaling, r-stress MDS for ratio, interval and nonmetric scaling, power stress for interval and ratio optimal scaling, restricted power-stress with ratio and interval optimal scaling, approximate power-stress with ratio scaling, curvilinear component analysis with ratio, interval and ordinal optimal scaling, power curvilinear component analysis with ratio, interval and ordinal optimal scaling, Box-Cox MDS and local MDS. Some functions are suitably flexible to allow any other sensible combination of explicit power transformations for weights, distances and input proximities with implicit ratio, interval or ordinal optimal scaling of the input proximities. Most functions use a majorization algorithm.
Details
The package provides:
Models:
alscal... ALSCAL (s-stress) MDS with ratio, interval optimal scaling
elscal.. Elastic scaling MDS with ratio, interval optimal scaling
multiscale... Multiscale MDSwith ratio, interval optimal scaling
rstressMin .. R-Stress MDS with ratio, interval, ordinal optimal scaling
powerStressMin... power stress MDS (POST-MDS) with ratio, interval optimal scaling
apStressMin... approximate POST-MDS with ratio, interval optimal scaling
rpowerStressMin... restricted POST-MDS with ratio, interval optimal scaling
clca ... curvilinear component analysis with ratio, interval, ordinal optimal scaling
pclca ... power curvilinear component analysis with ratio, interval, ordinal optimal scaling
bcmds ... Box-Cox MDS with ratio optimal scaling
lmds... Local MDS with ratio optimal scaling
sammonmap... Sammon mapping with ratio, interval optimal scaling
Classes and Methods: The objects are of classes that extend the S3 classes smacof and smacofB. For the objects returned by the high-level functions S3 methods for standard generics were implemented, including print, coef, residuals, summary, plot, plot3dstatic. Wrappers and convenience functions for the model objects:
bootmds ... bootstrapping and MDS model
biplotmds ... MDS Biplots
icExploreGen ... Expore initial configurations
jackmds ... jackknife for MDS
multistart ... multistart function for MDS
permtest ... permutation test for MDS
Wrappers:
cmdscale ... stats::cmdscale but returns an S3 objects to be used with smacof classes
sammon... MASS::sammon but returns S3 objects to be used with smacof classes
Authors: Thomas Rusch, Jan de Leeuw, Lisha Chen, Patrick Mair
Maintainer: Thomas Rusch
Examples
data(BankingCrisesDistances)
res<-rStressMin(BankingCrisesDistances[,1:69],type="ordinal",r=2)
res
summary(res)
plot(res)
plot(res,"transplot")
plot(res,"Shepard")
msres<- multistart(res)
res2<-msres$best
permtest(res2)