sim2diss {smacof} | R Documentation |
Utility function for converting similarities into dissimilarities. Different methods are provided.
sim2diss(similmat, method = "corr", to.dist = TRUE)
similmat |
Similarity matrix (not necessarily symmetric, nor quadratic) |
method |
Various methods for converting similarities into dissimilarities: "corr" , "neglog" , "counts" , or an integer value (see details) |
to.dist |
If TRUE , object of class dist is produced |
We provide the following methods for converting similarities S into dissimilarities D: "corr"
is suited for correlation matrices and takes D = sqrt(1-S). "neglog"
takes the negative logarithm in terms of -log(S). Having frequencies, "counts"
is appropriate which does -log((S[i,j]*S[j,i)/(S[i,i]*S[j,j])). The user can specify also an integer value v. In this case sim2diss()
computes v-S.
Returns dissimiarities either as matrix or as dist object.
## Converting Ekman data (similarities) into dissimilarities by subtraction from 1 data(ekman) ekman.diss <- sim2diss(ekman, method = 1) res <- smacofSym(ekman.diss)