elastic.distance {fdasrvf}

Calculates two elastic distance

Description

This functions calculates the distances between functions in R^1 D_y and D_x, where function 1 is aligned to function 2

Usage

elastic.distance(f1, f2, time, lambda = 0, pen = "roughness")

Arguments

f1

sample function 1, provided as a vector of length M

f2

sample function 2, provided as a vector of length M

time

sample points of functions, provided as a vector of length M

lambda

controls amount of warping (default = 0)

pen

alignment penalty (default = "roughness") options are second derivative ("roughness"), geodesic distance from id ("geodesic"), and norm from id ("norm")

Value

Returns a list containing

Dy

amplitude distance

Dx

phase distance

References

Srivastava, A., Wu, W., Kurtek, S., Klassen, E., Marron, J. S., May 2011. Registration of functional data using fisher-rao metric, arXiv:1103.3817v2.

Tucker, J. D., Wu, W., Srivastava, A., Generative Models for Function Data using Phase and Amplitude Separation, Computational Statistics and Data Analysis (2012), 10.1016/j.csda.2012.12.001.

Examples

distances <- elastic.distance(
  f1 = simu_data$f[, 1],
  f2 = simu_data$f[, 2],
  time = simu_data$time
)