mdsunique {asymmetry} R Documentation

## MDS Model with Unique Dimensions

### Description

This asymmetric MDS model proposed by Holman (1979) and further analyzed by Bentler & Weeks (1982) has both common and unique dimensions. The common dimensions are shared by all other objects, whereas unique dimension apply to one object. A unique dimension has a non zero value for only one object, the coordinates for the other objects are zero. There are as many unique dimensions as there are objects. An asymmetric version of this model has two sets of unique dimensions: one for the rows and one for the columns. The distance in this model is defined as:

d_{ij}(X)=\sqrt{\sum_{s=1}^p (x_{is}-x_{js})^2 + r_{i}^{2}+c_{j}^{2}}.

### Usage

mdsunique(data, weight = NULL, ndim = 2, verbose = FALSE, itmax = 125, eps = 1e-12)



### Arguments

 data Asymmetric dissimilarity matrix weight Optional non-negative matrix with weights, if no weights are given all weights are set equal to one ndim Number of dimensions verbose If true, prints the iteration history to screen itmax Maximum number of iterations eps Convergence criterion for Stress

### Value

 ndim Number of dimensions of the configuration fulldim Number of dimensions of the full model, this equals ndim + the number of rows + the number of columns stress The raw stress for this model confi Returns the configuration matrix of shared dimensions of this multidimensional scaling model X Returns the configuration matrix of the full model consisting of shared and unique dimensions niter The number of iterations for the algorithm to converge nobj The number of objects in this model resid A matrix with raw residuals model Name of this asymmetric multidimensional scaling model row The unique dimensions for the rows col The unique dimensions for the columns unique The unique dimensions

### Examples

## Not run:
data("studentmigration")
mm<-studentmigration
mm[mm==0]<-.5          # replace zeroes by a small number
mm <- -log(mm/sum(mm)) # convert similarities to dissimilarities
v<-mdsunique(mm, ndim = 2, itmax = 2100, verbose=FALSE, eps = .0000000001)
plot(v, yplus = .3)

## End(Not run)



[Package asymmetry version 2.0.4 Index]