asymPermute: Assess differences in amount and direction of asymmetric...

In Morpho: Calculations and Visualisations Related to Geometric Morphometrics

Assess differences in amount and direction of asymmetric variation (only object symmetry)

Description

Assess differences in amount and direction of asymmetric variation (only object symmetry)

Usage

asymPermute(x, groups, rounds = 1000, which = NULL)

Arguments

x	object of class symproc result from calling procSym with pairedLM specified
groups	factors determining grouping.
rounds	number of permutations
which	select which factorlevels to use, if NULL, all pairwise differences will be assessed after shuffling pooled data.

Value

dist	difference between vector lengths of group means
angle	angle (in radians) between vectors of group specific asymmetric deviation
means	actual group averages
p.dist	p-value obtained by comparing the actual distance to randomly acquired distances
p.angle	p-value obtained by comparing the actual angle to randomly acquired angles
permudist	vector containing differences between random group means' vector lenghts
permuangle	vector containing angles between random group means' vectors
groupmeans	array with asymmetric displacement per group
levels	character vector containing the factors used

Note

This test is only sensible if between-group differences concerning directional asymmetry have been established (e.g. by applying a MANOVA on the "asymmetric" PCscores (see also procSym) and one wants to test whether these can be attributed to differences in amount and/or direction of asymmetric displacement. Careful interpretation for very small amounts of directional asymmetry is advised. The Null-Hypothesis is that we have the same directional asymmetry in both groups. If you want to test whether the angle between groups is similar, please use angleTest.

See Also

procSym

Morpho documentation built on June 22, 2024, 7:19 p.m.