refund (version 0.1-37)

cmdscale_lanczos: Faster multi-dimensional scaling

Description

This is a modified version of {cmdscale} that uses the Lanczos procedure ([mgcv]{slanczos}) instead of eigen. Called by {smooth.construct.pco.smooth.spec}.

Usage

cmdscale_lanczos(d, k = 2, eig = FALSE, add = FALSE, x.ret = FALSE)

Value

as {cmdscale}

Arguments

d

a distance structure as returned by {dist}, or a full symmetric matrix of distances or dissimilarities.

k

the maximum dimension of the space which the data are to be represented in; must be in {1, 2, ..., n-1}.

eig

logical indicating whether eigenvalues should be returned.

add

logical indicating if the additive constant of Cailliez (1983) should be computed, and added to the non-diagonal dissimilarities such that the modified dissimilarities are Euclidean.

x.ret

indicates whether the doubly centred symmetric distance matrix should be returned.

Author

David L Miller, based on code by R Core.

References

Cailliez, F. (1983). The analytical solution of the additive constant problem. Psychometrika, 48, 343-349.

See Also

{smooth.construct.pco.smooth.spec}