| jackmds.pcops {cops} | R Documentation |
MDS Jackknife for pcops objects
Description
These methods perform an MDS Jackknife and plot the corresponding solution.
Usage
## S3 method for class 'pcops'
jackmds(object, eps = 1e-06, itmax = 100, verbose = FALSE)
Arguments
object |
Object of class pcops. |
eps |
Convergence criterion |
itmax |
Maximum number of iterations |
verbose |
If 'TRUE', intermediate stress is printed out. |
Details
In order to examine the stability solution of an MDS, a Jackknife on the configurations can be performed (see de Leeuw & Meulman, 1986) and plotted. The plot shows the jackknife configurations which are connected to their centroid. In addition, the original configuration (transformed through Procrustes) is plotted. The Jackknife function itself returns also a stability measure (as ratio of between and total variance), a measure for cross validity, and the dispersion around the original smacof solution.
Note that this jackknife only resamples the configuration given the selected hyperparameters, so uncertainty with respect to the hyperparameetr selection is not incorporated.
Value
An object of class 'smacofJK', see jackmds. With values
smacof.conf: Original configuration
jackknife.confboot: An array of n-1 configuration matrices for each Jackknife MDS solution
comparison.conf: Centroid Jackknife configurations (comparison matrix)
cross: Cross validity
stab: Stability coefficient
disp: Dispersion
loss: Value of the loss function (just used internally)
ndim: Number of dimensions
call: Model call
niter: Number of iterations
nobj: Number of objects
Examples
diso<-kinshipdelta
fit <- pcops(diso,loss="stress")
res.jk <- jackmds(fit)
plot(res.jk)