lmds {stops} | R Documentation |
An MDS version for local MDS (Chen & Buja 2006)
lmds(delta, init = NULL, ndim = 3, k = 2, tau = 1, itmax = 5000, verbose = 0)
delta |
dissimilarity or distance matrix |
init |
initial configuration. If NULL a classical scaling solution is used. |
ndim |
the dimension of the configuration |
k |
the k neighbourhood parameter |
tau |
the penalty parameter (suggested to be in [0,1]) |
itmax |
number of optimizing iterations, defaults to 5000. |
verbose |
prints progress if > 4. |
Note that k and tau are not independent. It is possible for normalized stress to become negative if the tau and k combination is so that the absolute repulsion for the found configuration dominates the local stress substantially less than the repulsion term does for the solution of D(X)=Delta, so that the local stress difference between the found solution and perfect solution is nullified. This can typically be avoided if tau is between 0 and 1. If not, set k and or tau to a smaller value.
Lisha Chen & Thomas Rusch
dis<-smacof::kinshipdelta res<- lmds(as.matrix(dis),k=2,tau=0.1) res summary(res) plot(res)