Morpho (version 2.2)

symmetrize: create a perfectly symmetric version of landmarks

Description

create a perfectly symmetric version of landmarks

Usage

symmetrize(x, pairedLM)

Arguments

x

k x m matrix 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.

Value

• a symmetrized version of x

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)
deformGrid3d(symx,boneLM[,,2])