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Extract raster values at sites

geo_extract.Rd

Joins CHELSA, WorldClim or SRTM-style rasters (a terra::SpatRaster or a file path) to site coordinates. Layer names become columns. Points that fall on NA cells keep NA in those columns.

Usage

geo_extract(data, raster, lon = lon, lat = lat, method = "simple", bind = TRUE)

Arguments

data

A data frame or sf object with site coordinates.

raster

A terra::SpatRaster, a file path, or a list of either.

lon, lat

<data-masking> Coordinate columns when data is not sf.

method

Extraction method passed to terra::extract(), default "simple".

bind

Bind extracted columns onto data? If FALSE, return only the extracted tibble.

Value

A tibble (or sf tibble) with one column per raster layer.

Examples

r <- terra::rast(ncols = 36, nrows = 18, xmin = -180, xmax = 180,
  ymin = -90, ymax = 90, crs = "EPSG:4326")
terra::values(r) <- seq_len(terra::ncell(r))
names(r) <- "demo"
sites <- tibble::tibble(site = "a", lon = 147, lat = -9)
geo_extract(sites, r, lon, lat)
#> # A tibble: 1 × 4
#>   site    lon   lat  demo
#>   <chr> <dbl> <dbl> <int>
#> 1 a       147    -9   357