rotations (version 0.2)

center: Center rotation data

Description

This function will take the sample Rs and return the sample Rs centered at S. That is, if each row of Rs is R then the returned sample is $S^\top R$. If S is the true center then the projected mean should be close to the 3-by-3 identity matrix.

Usage

center(x, S)
  ## S3 method for class 'SO3':
center(x, S)
  ## S3 method for class 'Q4':
center(x, S)

Arguments

x

$n\times p$ matrix where each row corresponds to a random rotation in matrix ($p=9$) or quaternion ($p=4$) form.

S

the rotation about which to center x.

Value

• The centered sample.

Examples

Rs<-ruars(5,rcayley)
cRs<-center(Rs,mean(Rs))
mean(cRs) #Should be close to identity matrix