| time_warping {fdasrvf} | R Documentation |
This function aligns a collection of functions using the elastic square-root slope (srsf) framework.
time_warping( f, time, lambda = 0, method = "mean", showplot = TRUE, smooth_data = FALSE, sparam = 25, parallel = FALSE, omethod = "DP", MaxItr = 20 )
f |
matrix (N x M) of M functions with N samples |
time |
vector of size N describing the sample points |
lambda |
controls the elasticity (default = 0) |
method |
warp and calculate to Karcher Mean or Median (options = "mean" or "median", default = "mean") |
showplot |
shows plots of functions (default = T) |
smooth_data |
smooth data using box filter (default = F) |
sparam |
number of times to apply box filter (default = 25) |
parallel |
enable parallel mode using |
omethod |
optimization method (DP,DP2,RBFGS) |
MaxItr |
maximum number of iterations |
Returns a fdawarp object containing
f0 |
original functions |
fn |
aligned functions - matrix (N x M) of M functions with N samples |
qn |
aligned SRSFs - similar structure to fn |
q0 |
original SRSF - similar structure to fn |
fmean |
function mean or median - vector of length N |
mqn |
SRSF mean or median - vector of length N |
gam |
warping functions - similar structure to fn |
orig.var |
Original Variance of Functions |
amp.var |
Amplitude Variance |
phase.var |
Phase Variance |
qun |
Cost Function Value |
Srivastava, A., Wu, W., Kurtek, S., Klassen, E., Marron, J. S., May 2011. Registration of functional data using fisher-rao metric, arXiv:1103.3817v2 [math.ST].
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.
## Not run:
data("simu_data")
out = time_warping(simu_data$f,simu_data$time)
## End(Not run)