sdm_area: Create a 'sdm_area' object
In caretSDM: Build Species Distribution Modeling using 'caret'

sdm_area

R Documentation

Create a `sdm_area` object

Description

This function creates a new sdm_area object.

Usage

sdm_area(x, cell_size = NULL, crs = NULL, variables_selected = NULL,
                gdal = TRUE, crop_by = NULL, lines_as_sdm_area = FALSE)

get_sdm_area(i)

add_sdm_area(sa1, sa2)

Arguments

`x`	A shape or a raster. Usually a shape from `sf` class, but rasters from `stars`, `rasterStack` or `SpatRaster` class are also allowed.
`cell_size`	`numeric`. The cell size to be used in models.
`crs`	`numeric`. Indicates which EPSG should the output grid be in. If `NULL`, epsg from `x` is used.
`variables_selected`	A `character` vector with variables in `x` to be used in models. If `NULL` (standard), all variables in `x` are used.
`gdal`	Boolean. Force the use or not of GDAL when available. See details.
`crop_by`	A shape from `sf` to crop `x`.
`lines_as_sdm_area`	Boolean. If `x` is a `sf` with LINESTRING geometry, it can be used to model species distribution in lines and not grid cells.
`i`	A `sdm_area` or a `input_sdm` object.
`sa1`	A `sdm_area` object.
`sa2`	A `sdm_area` object.

Details

The function returns a sdm_area object with a grid built upon the x parameter. There are two ways to make the grid and resample the variables in sdm_area: with and without gdal. As standard, if gdal is available in you machine it will be used (gdal = TRUE), otherwise sf/stars will be used. get_sdm_area will return the grid built by sdm_area. add_sdm_area will sum two sdm_area objects. As geoprocessing in caretSDM is performed using sf objects, add_sdm_area simply applies a rbind in the two different areas.

Value

A sdm_area object containing:

`grid`	`sf` with `POLYGON` geometry representing the grid for the study area.
`cell_size`	`numeric` information regarding the size of the cell used to rescale variables to the study area, representing also the cell size in the `grid`.

Author(s)

Luíz Fernando Esser (luizesser@gmail.com) and Reginaldo Ré. https://luizfesser.wordpress.com

Examples

# Create sdm_area object:
sa_area <- sdm_area(parana, cell_size = 50000, crs = 6933)

# Create sdm_area using a subset of rivs (lines):
sa_rivers <- sdm_area(rivs[c(1:100),], cell_size = 100000, crs = 6933, lines_as_sdm_area = TRUE)

caretSDM documentation built on Aug. 29, 2025, 5:17 p.m.