Morpho (version 1.0-1)

rotonto: rotates, translates and scales one matrix onto an other using Procrustes fitting

Description

rotate a matrix onto an other without loosing information about the location of the targetmatrix and reverse this transformations using rotreverse

Usage

rotonto(x, y, scale = FALSE, signref = TRUE, reflection = TRUE, weights
= NULL, centerweight = FALSE)
rotreverse(mat,rot)

Arguments

x

k x m matrix to be rotated onto (targetmatrix)

y

k x m matrix which will be rotated (reference matrix)

scale

logical: scale matrix to minimize sums of squares

signref

logical: report if reflections were involved in the rotation

mat

matrix on which the reverse transformations have to be applied

rot

an object resulting from the former application of rotonto

reflection

allow reflections.

weights

vector of length k, containing weights for each landmark.

centerweight

logical: if weights are defined and centerweigths=TRUE, the matrix will be centered according to these weights instead of the barycenter.

Value

• yrot
  rotated and translated matrix
• Y
  centred and rotated reference matrix
• X
  centred target matrix
• trans
  vector between original position of target and centered reference (during rotation process)
• transy
  vector between original position of reference and centered reference (during rotation process)
• gamm
  rotation matrix
• bet
  scaling factor applied
• reflect
  if reflect = 1, reflections are involved in the superimposition. Else, reflect = 0

References

Lissitz, R. W., Sch6nemann, P. H., & Lingoes, J. C. (1976). A solution to the weighted Procrustes problem in which the transformation is in agreement with the loss function. Psychometrika, 41,547-550.

See Also

rotmesh.onto

Examples

library(shapes)
lims <- c(min(gorf.dat[,,1:2]),max(gorf.dat[,,1:2]))
rot <- rotonto(gorf.dat[,,1],gorf.dat[,,2]) ### rotate the second onto the first config
plot(rot$yrot,pch=19,xlim=lims,ylim=lims) ## view result
points(gorf.dat [,,2],pch=19,col=2) ## view original config
rev1 <- rotreverse(rot$yrot,rot)
points(rev1,cex=2) ### show inversion by larger circles around original configuration