stats.ecors: Descritive statistics on ecors objects

In fredtaka/ecors: Remote Sensing data acquisition and processing for ecology with Google Earth Engine

Descritive statistics on ecors objects

Description

Performs descriptive statistics on study polygons at defined sampling periods.

Usage

stats.ecors(
  x,
  edge.pixels = "weighted",
  remove.samples = list(num.pixelOK = NULL, prop.pixelOK = 0.9),
  summarizing = "all",
  by.image.save = T,
  summary.save = T,
  stats = list(mean = T, median = T, sd = T, count = F),
  lower.cutoff = NULL,
  upper.cutoff = NULL,
  bands.index.subset = NULL,
  spreadsheet.folder = getwd()
)

Arguments

x	ecors object (from get.ecors).
edge.pixels	choose the treatment for pixels that coincide with the edges of the polygons: "weighted" uses the value of these pixels in the descriptive statistic weighted by the proportion of the area inside the polygon, "centroid" ignores pixels with the centroid outside the polygon.
remove.samples	removes sample units that were misrepresented due to bad pixel removal. Minimum number of good pixels (num.pixelOK) and/or minimum proportion of good pixels (prop.pixelOK) can be selected.
summarizing	selects whether the data will be summarized by year ("yearly") or for the entire evaluated period ("all"). The "yearly" option considers a year as every 12 months starting from the initial month of image collection.
by.image.save	save a csv file with descriptive statistics for each image?
summary.save	save a csv file with descriptive statistics summarizing all the images?
stats	enables/disables the calculation of mean, median, standard deviation (sd) or count (of pixels in the range of values between lower.cutoff and upper.cutoff).
lower.cutoff	Lower threshold values to ignore pixels in all stats (required for count). It must be a vector with a size equal to the number of bands/indexes to be analyzed.
upper.cutoff	Upper threshold values to ignore pixels in all stats (required for count). It must be a vector with a size equal to the number of bands/indexes to be analyzed.
bands.index.subset	Subset of bands to use for statistics.
spreadsheet.folder	local folder to save csv files.

Value

List with result tables and metadata. If enabled, csv files will be saved with tables (two for each descriptive statistics): results.mean.samples.csv, summary.mean.samples.csv, results.median.samples.csv, summary.median.samples.csv, results.sd.samples.csv, summary.sd.samples.csv, results.count.samples.csv, summary.count.samples.csv.

References

https://developers.google.com/earth-engine/guides/reducers_weighting

Examples

#get a ecors class object
FAL.IBGE.JBB<-sf::st_read(system.file("extdata/FAL.IBGE.JBB.gpkg", package="ecors"))
test.plots<-sf::st_read(system.file("extdata/Plots_tests.gpkg", package="ecors"))
test.points<-sf::st_read(system.file("extdata/Points_tests.gpkg", package="ecors"))

#library(ecors)
d2020<-get.ecors(site=FAL.IBGE.JBB, points=test.points, plots=test.plots, buffer.points=500, buffer.plots=500,
    eval.area="site", projected=F, custom.crs=32723,
    collection="LANDSAT/LC08/C02/T1_L2", start=c("2020-01-01"), end=c("2020-12-31"),
    bands.eval=c("SR_B3","SR_B4"), bands.vis=F, indices=c("NDVI"), resolution=30,
    pOK=0.3, c.prob=NULL, c.dist=100, clouds.sentinel=NULL, cirrus.threshold=NULL, NIR.threshold=NULL, CDI.threshold=NULL, dmax.shadow=NULL,
    seasons=list(s1=c(11,12,1,2), s2=c(3,4), s3=c(5,6,7,8), s4=c(9,10)), group.by="season", composite=NULL)

allpixels<-stats.ecors(x=d2020, edge.pixels="weighted", remove.samples=list(num.pixelOK=10,prop.pixelOK=0.8),
                  summarizing="all", by.image.save=T, summary.save=T,
                  stats=list(mean=T,median=F,sd=F,count=F),spreadsheet.folder=getwd() )

rangepixels<-stats.ecors(x=d2020, edge.pixels="weighted", remove.samples=list(num.pixelOK=10,prop.pixelOK=0.8),
                  summarizing="all", by.image.save=T, summary.save=T,
                  stats=list(mean=T,median=F,sd=F,count=T), lower.cutoff=c(9000,8500), upper.cutoff=c(10000,10000), bands.index.subset=c("SR_B3","SR_B4"),
                  spreadsheet.folder=getwd() )

fredtaka/ecors documentation built on Aug. 26, 2022, 6:58 a.m.