get_shape_distance: Computes the distance between two shapes

In fdasrvf: Elastic Functional Data Analysis

Computes the distance between two shapes

Description

Computes the distance between two shapes

Usage

get_shape_distance(
  q1fun,
  q2fun,
  alignment = FALSE,
  rotation = FALSE,
  scale = FALSE,
  lambda = 0,
  M = 200L
)

Arguments

q1fun	A function that takes a numeric vector s of values in [0, 1] as input and returns the values of the first SRVF at s.
q2fun	A function that takes a numeric vector s of values in [0, 1] as input and returns the values of the second SRVF at s.
alignment	A boolean value specifying whether the two SRVFs should be optimally aligned before computing the distance. Defaults to FALSE.
rotation	A boolean value specifying whether the two SRVFs should be optimally rotated before computing the distance. Defaults to FALSE.
scale	A boolean value specifying whether the two SRVFs should be projected onto the Hilbert sphere before computing the distance. Defaults to FALSE.
lambda	A numeric value specifying the regularization parameter for the optimal alignment. Defaults to 0.
M	An integer value specifying the number of points to use when searching for the optimal rotation and alignment. Defaults to 200L.

Value

A list with the following components:

• amplitude_distance: A numeric value storing the amplitude distance between the two SRVFs.

• phase_distance: A numeric value storing the phase distance between the two SRVFs.

• optimal_warping: A function that takes a numeric vector s of values in [0, 1] as input and returns the optimal warping function evaluated at s.

• q1fun_modified: A function that takes a numeric vector s of values in [0, 1] as input and returns the first SRVF modified according to the optimal alignment, rotation, and scaling.

• q2fun_modified: A function that takes a numeric vector s of values in [0, 1] as input and returns the second SRVF modified according to the optimal alignment, rotation, and scaling.

Examples

q1 <- curve2srvf(beta[, , 1, 1])
q2 <- curve2srvf(beta[, , 1, 2])
get_shape_distance(q1, q2)

fdasrvf documentation built on Nov. 5, 2025, 5:51 p.m.