Standard Deviation of Functional Data
Evaluate the standard deviation of a set of functions in a functional data object.
sd.fd(fdobj) std.fd(fdobj) stdev.fd(fdobj) stddev.fd(fdobj)
fdobj |
a functional data object. |
The multiple aliases are provided for compatibility with previous versions and with other languages. The name for the standard deviation function in R is 'sd'. Matlab uses 'std'. S-Plus and Microsoft Excal use 'stdev'. 'stddev' was used in a previous version of the 'fda' package and is retained for compatibility.
a functional data object with a single replication
that contains the standard deviation of the one or several functions in
the object fdobj.
liptime <- seq(0,1,.02)
liprange <- c(0,1)
# ------------- create the fd object -----------------
# use 31 order 6 splines so we can look at acceleration
nbasis <- 51
norder <- 6
lipbasis <- create.bspline.basis(liprange, nbasis, norder)
lipbasis <- create.bspline.basis(liprange, nbasis, norder)
# ------------ apply some light smoothing to this object -------
Lfdobj <- int2Lfd(4)
lambda <- 1e-12
lipfdPar <- fdPar(lipbasis, Lfdobj, lambda)
lipfd <- smooth.basis(liptime, lip, lipfdPar)$fd
names(lipfd$fdnames) = c("Normalized time", "Replications", "mm")
lipstdfd <- sd.fd(lipfd)
plot(lipstdfd)
all.equal(lipstdfd, std.fd(lipfd))
all.equal(lipstdfd, stdev.fd(lipfd))
all.equal(lipstdfd, stddev.fd(lipfd))Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.