Morpho (version 2.12)

symmetrize: create a perfectly symmetric version of landmarks

Description

create a perfectly symmetric version of landmarks

Usage

symmetrize(x, pairedLM)

Value

a symmetrized version of x

Arguments

x

k x m matrix or k x m x n array, with rows containing landmark coordinates

pairedLM

A X x 2 matrix containing the indices (rownumbers) of the paired LM. E.g. the left column contains the lefthand landmarks, while the right side contains the corresponding right hand landmarks.

Details

the landmarks are reflected and relabled according to pairedLM and then rotated and translated onto x. Both configurations are then averaged to obtain a perfectly symmetric one.

References

Klingenberg CP, Barluenga M, and Meyer A. 2002. Shape analysis of symmetric structures: quantifying variation among individuals and asymmetry. Evolution 56(10):1909-1920.

Examples

data(boneData)
left <- c(4,6,8)
right <- c(3,5,7)
pairedLM <- cbind(left,right)
symx <- symmetrize(boneLM[,,2],pairedLM)
if (FALSE) {
deformGrid3d(symx,boneLM[,,2])
}