Momocs (version 0.2-6)

procGPAlign(Coo): Performs a Generalized Procrustes Alignement on a Coo object.

Description

Performs a Generalized Procrustes Alignement on a Coo object, providing that landmarks have previously been defined.

Usage

procGPAlign(Coo, tol=1e-30)

Arguments

Coo

The Coo object.

tol

thresold for GPA. See procGPA in shapes package.

Value

• Returns a Coo with centered, rotated and scaled outlines.

Details

If landmarks are defined, their coordinates are used for the GPA alignment, with the procGPA in shapes. Then the original outlines are rotated and scaled accordingly.

See Also

defLandmarks, cooLandmarks.

Examples

data(hearts)
# we add a lot of perturbations below
for (i in 1:[e-mail]){
  coo.i <- hearts@coo[[i]] * runif(1, 0, 20)
  coo.i <- coo.rotate(coo.i, runif(1, 0, 2*pi))
  coo.i <- coo.trans(coo.i, runif(1, 0, 200), runif(1, 0, 200))
  hearts@coo[[i]] <- coo.i
}

def.par <- par(no.readonly = TRUE)
layout(matrix(1:3, 1, 3))
stack(hearts, borders="black", ldk.pch=20, ldk.cex=0.5)
title("Troubled hearts")
# we perform GPA
hearts2 <- procGPAlign(hearts)
stack(hearts2, borders="#1A1A1A22", ldk.pch=20, ldk.cex=0.5)
title("After GP alignement")
# we register a new baseline
hearts3 <- baseline(hearts2, 2, 4)
stack(hearts3, borders="#1A1A1A22", ldk.pch=20, ldk.cex=0.5)
title("And with a new baseline")
par(def.par)