lidaRtRee (version 4.0.8)

clouds_metrics: Computes metrics on list of point clouds

Description

Computes metrics for a list of LAS objects (should be normalized point clouds). Calls the function cloud_metrics on each element and then arranges the results in a data.frame.

Usage

clouds_metrics(
  llasn,
  func = ~lidR::stdmetrics(X, Y, Z, Intensity, ReturnNumber, Classification, dz = 1)
)

Value

A data frame with metrics in columns corresponding to LAS objects of the list (lines)

Arguments

llasn

list of LAS objects

func

function. function applied on each element to compute metrics, default function is stdmetrics from package lidR

See Also

cloud_metrics, stdmetrics, aba_metrics, pixel_metrics

Examples

# load LAS file
LASfile <- system.file("extdata", "las_chablais3.laz", package="lidaRtRee")
las_chablais3 <- lidR::readLAS(LASfile)

# set number of threads
lidR::set_lidr_threads(2)
# extract four point clouds from LAS object
llas <- list()
llas[["A"]] <- lidR::clip_circle(las_chablais3, 974350, 6581680, 10)
llas[["B"]] <- lidR::clip_circle(las_chablais3, 974390, 6581680, 10)
llas[["C"]] <- lidR::clip_circle(las_chablais3, 974350, 6581640, 10)
# normalize point clouds
llas <- lapply(llas, function(x) {
  lidR::normalize_height(x, lidR::tin())
})

# compute metrics
clouds_metrics(llas)

# compute metrics with user-defined function
# mean and standard deviation of first return points above 10 m
user_func <- function(z, rn, hmin = 10) {
  # first return above hmin subset
  dummy <- which(z >= hmin & rn == 1)
  return(list(
    mean.z = mean(z[dummy]),
    sd.z = stats::sd(z[z > hmin])
  ))
}
clouds_metrics(llas, func = ~ user_func(Z, ReturnNumber, 10))