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Create a mask layer based on a simple feature object

Source: R/layer_mask.R
layer_mask.Rd

Returns a mask for an area or areas as a simple feature object. neatline = TRUE only works for this layer if data is passed directly; not inherited.

Usage

layer_mask(
  data = NULL,
  dist = NULL,
  diag_ratio = NULL,
  unit = NULL,
  asp = NULL,
  crs = getOption("maplayer.crs", default = 3857),
  fill = "white",
  color = NA,
  alpha = 0.5,
  mask = NULL,
  neatline = FALSE,
  expand = TRUE,
  ...
)

set_mask(x = NULL, mask = TRUE, data = NULL, crs = NULL, ...)

Arguments

data

sf, sfc, or bbox object. If dist, diag_ratio, and/or asp are provided, data is adjusted to set the boundaries of the mask. If data is not provided, mask is required. If data is NA, mask is continuous otherwise the data is erased from the mask area.

dist

buffer distance in units. Optional.

diag_ratio

ratio of diagonal distance of area's bounding box used as buffer distance. e.g. if the diagonal distance is 3000 meters and the "diag_ratio = 0.1" a 300 meter will be used. Ignored when dist is provided.

unit

Units for buffer. Supported options include "meter", "foot", "kilometer", and "mile", "nautical mile" Common abbreviations (e.g. "km" instead of "kilometer") are also supported. Distance in units is converted to units matching GDAL units for x; defaults to "meter"

asp

Aspect ratio of width to height as a numeric value (e.g. 0.33) or character (e.g. "1:3"). If numeric, get_asp() returns the same value without modification.

crs

Coordinate reference system of bounding box to return; defaults to NULL which maintains the crs of the input object.

fill

mask fill color; defaults to "white"

color

mask edge color; defaults to NA

alpha

mask alpha/transparency; defaults to 0.5

mask

A sf, sfc, or bbox object to define the mask area. diag_ratio, dist, and asp parameters are ignored if a mask is provided. defaults to NULL

neatline

A logical object, CoordSf object, or a list containing a CoordSf object (typically from layer_neatline()) added to layer by set_neatline().

  • If logical and TRUE, add a neatline layer using data, crs and any additional parameters passed to ... If logical and FALSE, return x as is.

  • If object from layer_neatline(), add it as is.

expand

If TRUE, the default, adds a small expansion factor to the limits to ensure that data and axes don't overlap. If FALSE, limits are taken exactly from the data or xlim/ylim.

...

Additional parameters to pass to ggplot2::geom_sf()

x

A sf, sfc, bbox, sfg, Raster, Spatial, Extent, numeric, or character object (a place name passed to osmdata::getbb()). See as_bbox() for more details.

Value

ggplot2::geom_sf() function.