stress0: Zero-Iterations Stress

Description

Computes the stress for 0 iterations based on a starting configuration provided by the user.

Usage

stress0(delta, init, type = c("interval", "ratio", "ordinal", "mspline"), 
        weightmat = NULL, ties = "primary", spline.degree = 2, spline.intKnots = 2)

Value

delta: Observed dissimilarities, not normalized
dhat: Disparities (transformed proximities, approximated distances, d-hats)
confdist: Configuration distances
conf: Matrix of fitted configurations
stress: Stress-1 value
spp: Stress per point (stress contribution in percentages)
resmat: Matrix with squared residuals
rss: Residual sum-of-squares
weightmat: Weight matrix
ndim: Number of dimensions
init: Starting configuration
model: Name of smacof model
niter: Number of iterations
nobj: Number of objects
type: Type of MDS model

Arguments

delta: Either a symmetric dissimilarity matrix or an object of class "dist"
init: An initial configuration provided by the user
weightmat: Optional matrix with dissimilarity weights
type: MDS type: "interval", "ratio", "ordinal" (nonmetric MDS), or "mspline"
ties: Tie specification (ordinal MDS only): "primary", "secondary", or "tertiary"
spline.degree: Degree of the spline for "mspline" MDS type
spline.intKnots: Number of interior knots of the spline for "mspline" MDS type

Details

Computes stress-1 for a particular starting configuration the user needs to provide. It can also be helpful if the user wants to force a particular theoretical configuration (as specified in inits) on the data.

Examples

Run this code

## rectangle starting solution
rect_constr
stress0(rectangles, init = rect_constr)

## torgerson starting solution
tstart <- torgerson(rectangles)
stress0(rectangles, init = tstart)