smacof (version 1.8-13)

sim2diss: Converts similarites to dissimilarities

Description

Utility function for converting similarities into dissimilarities. Different methods are provided.

Usage

sim2diss(similmat, method = "corr", to.dist = TRUE)

Arguments

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

Value

Details

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 $v-S$.

Examples

## Converting Ekman data (similarities) into dissimilarities by subtraction from 1
data(ekman)
ekman.diss <- sim2diss(ekman, method = 1)
res <- smacofSym(ekman.diss)