reparam_curve {fdasrvf}

Align two curves

Description

This function aligns two SRVF functions using Dynamic Programming. If the curves beta1 and beta2 are describing multidimensional functional data, then rotation == FALSE and mode == 'O'

Usage

reparam_curve(
  beta1,
  beta2,
  lambda = 0,
  method = "DP",
  w = 0.01,
  rotated = TRUE,
  isclosed = FALSE,
  mode = "O"
)

Arguments

beta1

curve 1, provided as a matrix of dimensions n \times M for n-dimensional curve evaluated on M sample points

beta2

curve 1, provided as a matrix of dimensions n \times M for n-dimensional curve evaluated on M sample points

lambda

controls amount of warping (default = 0)

method

controls which optimization method. Options are Dynamic Programming ("DP"). (default = "DP")

w

controls LRBFGS (default = 0.01)

rotated

boolean if rotation is desired

isclosed

boolean if curve is closed

mode

Open ("O") or Closed ("C") curves

Value

return a List containing

gam

warping function

R

rotation matrix

tau

seed point

References

Srivastava, A., Klassen, E., Joshi, S., Jermyn, I., (2011). Shape analysis of elastic curves in euclidean spaces. Pattern Analysis and Machine Intelligence, IEEE Transactions on 33 (7), 1415-1428.

Examples

gam <- reparam_curve(beta[, , 1, 1], beta[, , 1, 5])$gam