ExtractMultiple: Extracting from Multiple Raster Layers

In barbehenna/KerkhoffPackage: Useful Code for Kerkhoff Lab Group

Usage

ExtractMultiple(raster_vector, gis_data, projection = NULL, filename = NULL,
  storeInDirectory = FALSE)

Arguments

raster_vector	A single raster layer or a vector
gis_data	A data frame containing longitude and latitude pairs
projection	User specified projection #may not do anything becasue extract may reset it
filename	A user specified name that the data will be saved as, instead of the default raster_data.csv
storeInDirectory	This boolean parameter asks wheter or not the user wants to store the data in the working directory.

Value

This function returns a data frame/matrix at each location specified by gis_data parameter. If storeInDirectory is TRUE, then it also saves the data to a file (defaults to raster_data.csv).

Note

I'm using a raster brick because, "while a RasterBrick has to refer to one multi-layer file or is in itself a multi-layer object with data loaded in memory, a RasterStack may 'virtually' connect several raster objects written to different files or in memory. Processing will be more efficient for a RasterBrick than for a RasterStack, but RasterStack has the advantage of facilitating pixel based calculations on separate raster layers." From http://geoscripting-wur.github.io/IntroToRaster/

Author(s)

Alton Barbehenn

Examples

ExtractMultiple(c(bio1, bio9), gis_data)
species_vector<-c("Abies amabilis", "Acer nigrum")
gis_data = BIEN.gis.species(species_vector)[2:3]
gis_data = na.omit(gis_data)
gis_data = unique(gis_data)
raster_vec <- c(raster("bio_1.bil"), raster("bio_9.bil"), raster("bio_4.bil"))
ExtractMultiple(raster_vector = raster_vec, gis_data = gis_data, filename = "your_file_name.csv", storeInDirectory = TRUE)

barbehenna/KerkhoffPackage documentation built on May 11, 2019, 6:23 p.m.