R: Center Functional Data

center.fd {fda} | R Documentation

## Center Functional Data

### Description

Subtract the pointwise mean from each of the functions in a functional data object; that is, to center them on the mean function.

### Usage

    center.fd(fdobj)

### Arguments

`fdobj` | a functional data object to be centered.

### Value

a functional data object whose mean is zero.

### See Also

`mean.fd`, `sum.fd`, `stddev.fd`, `std.fd`

### Examples

    daytime    <- (1:365)-0.5
    daybasis   <- create.fourier.basis(c(0,365), 365)
    harmLcoef  <- c(0,(2*pi/365)^2,0)
    harmLfd    <- vec2Lfd(harmLcoef, c(0,365))
    templambda <- 0.01
    tempfdPar  <- fdPar(daybasis, harmLfd, templambda)

    # do not run on CRAN because it takes too long.
    if(!CRAN()){
    tempfd     <- smooth.basis(daytime,
           CanadianWeather$dailyAv[,,"Temperature.C"], tempfdPar)$fd

    tempctrfd  <- center.fd(tempfd)

    plot(tempctrfd, xlab="Day", ylab="deg. C",
         main = "Centered temperature curves")
    }

[Package fda version 2.4.8 Index]