polyStatsLevel2AM: Compute descriptive statistics of GEDI Elevation and Height...

In carlos-alberto-silva/rGEDI: NASA's Global Ecosystem Dynamics Investigation (GEDI) Data Visualization and Processing

Compute descriptive statistics of GEDI Elevation and Height Metrics

Description

Computes a Series of Statistics from GEDI derived Elevation and Height Metrics (Level2A) within a given area defined or not by a polygon

Usage

polyStatsLevel2AM(level2AM, func, id=NULL)

Arguments

level2AM	A GEDI Level2AM object (output of getLevel2AM() function). An S4 object of class "data.table".
func	The function to be applied for computing the defined statistics
id	A vector containing the polygon id for each GEDI observation. Default is NULL

Value

Returns an S4 object of class data.table::data.table Containing Statistics of GEDI level2A defined metrics

See Also

https://lpdaac.usgs.gov/products/gedi02_av002/

Examples

# Specifying the path to GEDI level2A data (zip file)
outdir <- tempdir()
level2A_fp_zip <- system.file("extdata",
  "GEDI02_A_2019108080338_O01964_T05337_02_001_01_sub.zip",
  package = "rGEDI"
)

# Unzipping GEDI level2A data
level2Apath <- unzip(level2A_fp_zip, exdir = outdir)

# Reading GEDI level2A data (h5 file)
level2a <- readLevel2A(level2Apath = level2Apath)

# Specifying the path to shapefile
polygon_filepath <- system.file("extdata", "stands_cerrado.shp", package = "rGEDI")

# Reading shapefile as sf object
library(sf)
polygon <- sf::st_read(polygon_filepath)

# Extracting GEDI Eleveation and Relative Metrics (level2A)
level2AM <- getLevel2AM(level2a)
head(level2AM)

# Clipping GEDI data by geometry
level2AM_clip <- clipLevel2AMGeometry(level2AM, polygon, split_by = "id")

#' Define your own function
mySetOfMetrics <- function(x) {
  metrics <- list(
    min = min(x), # Min of x
    max = max(x), # Max of x
    mean = mean(x), # Mean of x
    sd = sd(x) # Sd of x
  )
  return(metrics)
}

# Computing the maximum of RH100
RH100max <- polyStatsLevel2AM(level2AM_clip, func = max(rh100), id = NULL)

# Computing the maximum of RH100 stratified by polygon
RH100max_poly <- polyStatsLevel2AM(level2AM_clip, func = max(rh100), id = NULL)

# Computing a serie statistics for GEDI metrics stratified by polygon
RH100metrics <- polyStatsLevel2AM(level2AM_clip,
  func = mySetOfMetrics(rh100),
  id = level2AM_clip$id
)

head(RH100metrics)

close(level2a)

carlos-alberto-silva/rGEDI documentation built on Oct. 18, 2024, 4:46 a.m.