R/flm_ftest.R

In Actigraphy: Actigraphy Data Analysis

flm_ftest <-
function(FD, basistype="fourier", nbasis=9, norder=4, ftest=TRUE, nperm=1000, xat, lb, mul=1){ 
	if(missing(FD)) 
		stop("Missing FD")
	
	cov <- FD$cov[,-1]
	grp <- ncol(cov)
	fd <- FD$fd
	L <- length(fd$argvals)
	npt <- ncol(fd$y)
	
	if(tolower(basistype) == "fourier"){
		fbase <- fda::create.fourier.basis(rangeval=c(0, L), nbasis)
	}else if(tolower(basistype) == "bspline"){
		fbase <- fda::create.bspline.basis(rangeval=c(0, L), nbasis, norder)
	}else{
		stop("basistype must be 'fourier' or 'bspline'.")
	}
	
	fpar <- fda::fdPar(fbase)
	
	xfdlist <- vector("list",grp)
	xfdlist[[1]] <- cov[,1]+0
	for(i in 2:grp) 
		xfdlist[[i]] <- cov[,i]+0
	betalist <- xfdlist
	
	for(i in 1:grp) 
		betalist[[i]] <- fpar 
	
	freg2 <- fda::fRegress(fd$fd, xfdlist, betalist)
	
	preact2 <- stats::predict(freg2$yhatfdobj, c(1:L))
	resid2 <- fd$y - preact2[,1:npt]
	sigma2 <- cov(t(resid2))
	fregstd2 <- fda::fRegress.stderr(freg2, fd$y2cMap, sigma2)
	
	Fratio <- NULL
	if(ftest){
		Fratio <- Ftest(fd$fd, xfdlist, betalist, NULL, nperm, 1:L, xaxt="n", mul=mul) 
		axis(1, at=xat, labels=lb)
	}
	
	return(list(freg=freg2, fregstd=fregstd2, Fratio=Fratio))
}