waveformlidar (version 1.2.0)

percentile.location: percentile.location

Description

The function allows you to calculate the time location position of energy percentile based on the given quantile within a waveform. With this information. In addition, you can calculate the energy percentile heights. Here, the percentile will be calculated from the top (more likely the canopy part) by defalut.

Usage

percentile.location(x, quan = seq(0.5, 1, 0.1), rescale = TRUE, top = TRUE)

Arguments

x

is the waveform intensities. If you have other information, you should delete these intensites before you run this function .

quan

is the quantile of energy you are interested in. Defalut is seq(0.5,1,0.1).

rescale

is to determine whether you want to rescale the waveform intensity or not. Here we used the minimum intensity of each waveform to conduct rescaling. Default is using rescaling.

top

is to tell whether we calculate the percentile from the top (where waveform starts or canopy) or from the bottom (where the waveform ends). Default is from the top.

Value

return the index or position of corressponding quantile energy of waveform starting from the top.

Examples

# NOT RUN {
data(return)
x<-return[1,]
#default
percentile.location(x)

#change the quantile
qr<-seq(0.45,0.99,0.05)
re1<-percentile.location(x,quan=qr)
###rescale affects your results
re2<-percentile.location(x,quan=qr,rescale = FALSE)
##after you get the index, you can convert them to the height
#based on temporal resolution or georeference information of this waveform.
# }