space_restriction {stppSim}

Space restriction raster map

Description

Builds a space restriction map from one or more shapefiles. A space restriction raster map showing the restriction levels of various features across the landscape. The function builds on raster- and SimRIv-packages.

Usage

space_restriction(shp, baseMap, res, binary = is.na(field),
field = NA, background = 1)

Arguments

shp

shapefile object containing features to serve as obstructions to the movement of walkers.

baseMap

if provided, a raster onto which to stack the restriction features (shp).

res

the desired pixel resolution of the raster to be created, when baseMap is not provided.

binary

if TRUE, the shapefile will be rasterized so that all features are assigned a value of 0 (minimum restriction level), and the background is assigned 1 (maximum restriction level).

field

a number in the range of [0-1] (i.e. restriction values) assigned to all features; or the name of a numeric field to extract such restriction values ([0 <= value < 1] for different classes of feature. Restriction value 0 and 1 indicate the lowest and the highest obstructions, respectively. Default: NULL.

background

the value in the range 0 and 1 to assign to all pixels that are not covered by any shapefile object.

Details

Helps to create a complete space restriction map with cell values ranging from 0 (⁠minimum restriction level⁠) and 1(⁠maximum restriction level⁠). All other areas not covered by any features are assigned the value of background. When stacking additional features to existing baseMap, only the areas covered by features are updated, while the remaining areas retain the original values of baseMap.

Value

Returns a raster map showing the restriction levels across the landscape.

References

1. Paul Murrell (2019). rasterize: Rasterize Graphical Output. R package version 0.1. https://CRAN.R-project.org/package=rasterize

2. Quaglietta L, Porto M (2019). SiMRiv: Individual-Based, Spatially-Explicit Simulation and Analysis of Multi-State Movements in River Networks and Heterogeneous Landscapes. R package version 1.0.4, <URL: https://CRAN.R-project.org/package=SiMRiv>.

Examples

#load boundary of Camden and land use data
load(file = system.file("extdata", "camden.rda",
package="stppSim"))
boundary = camden$boundary # get boundary
restrct_map <- space_restriction(shp = boundary,
res = 20, binary = TRUE)
#plot the result
#plot(restrct_space)
#Setting 'restrct_space' raster as basemap, the landuse
#map can now be stacked onto the basemap as follows:
landuse = camden$landuse # get landuse
restrct_Landuse <- space_restriction(shp = landuse,
baseMap = restrct_map,
res = 20, field = "restrVal", background = 1)
#plot(restrct_Landuse)