init_raster: Creates an empty raster for detection summaries
In bsmity13/ADePTR: Acoustic Detection Processing and Visualization Tool in R

Description Usage Arguments Details Value Examples

This function can take one of user-defined x- and y-limits, station locations, or a study area polygon and create an empty raster to use in the detection summary figures.

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init_raster(xlim = NULL, ylim = NULL, sta = NULL,
                   study_area = NULL, res = 0.01,
                   crs = sp::CRS("+init=epsg:4326"))

`xlim`	A numeric vector of length 2 giving user-defined x-limits. If `xlim` is provided, `ylim` must also be provided. These fields override both `sta` and `study_area`.
`ylim`	A numeric vector of length 2 giving user-defined y-limits. If `xlim` is provided, `ylim` must also be provided. These fields override both `sta` and `study_area`.
`sta`	A data.frame with x- and y-coordinates of all the stations in the study area. The x- and y-coordinates should be in columns named `"x"` and `"y"`, respectively. Ignored if `xlim` or `ylim` are provided. This field overrides `study_area`.
`study_area`	A polygon of class `sfc` from the package `sf` that delimits the study area.
`res`	A numeric vector of length 1 or 2 giving the size of a grid cell in units of the coordinate reference system. See `res` for details.
`crs`	A character or object of class CRS. Defines the coordinate reference system to use for the resulting raster. Should match the CRS of the input if applicable. Used by `raster` as the `crs` argument. Defaults to `(CRS("+init=epsg:4326"))`, indicating EPSG code 4326 for WGS 84 lat/long.

Behavior depends upon the input. Once the function reaches a valid input, it returns the raster without bothering to check if additional inputs were provided.

The order it checks in is:

xlim and ylim (must provide both)
sta (x- and y-coordinates should be named "x" and "y")
study_area (polygon of class sfc)

Returns an object of class RasterLayer

#Load sample data
data(acoustic)

#Using xlim and ylim
xlim <- c(-64.628, -64.612)
ylim <- c(17.770, 17.795)
r.lim <- init_raster(xlim = xlim, ylim = ylim)

#Use UTM
xlim <- c(321160, 335010)
ylim <- c(1965700, 1973810)
r.lim.utm <- init_raster(xlim = xlim, ylim = ylim,
                         res = 500, #units here are meters
                         crs = sp::CRS("+init=epsg:32620"))

#Using sta
r.sta <- init_raster(sta = acoustic$stations)

#Using study_area
r.sa <- init_raster(study_area = acoustic$study_area)

#Change the resolution (in CRS units)
r.sa2 <- init_raster(study_area = acoustic$study_area,
                     res = 0.0001)