Download friction surface from Malaria Atlas Project

Usage

get_friction_surface(
  shp = NULL,
  extent = NULL,
  transport_type = "walking",
  export = FALSE,
  output_dir = "."
)

shp: Area of interest, can be sf of SpatialPolygonDataFrame object, or character string for specific country (will use malariaAtlas shapefile).
extent: 2x2 matrix specifying the spatial extent within which raster data is desired, as returned by sp::bbox() - the first column has the minimum, the second the maximum values; rows 1 & 2 represent the x & y dimensions respectively (matrix(c("xmin", "ymin","xmax", "ymax"), nrow = 2, ncol = 2, dimnames = list(c("x", "y"), c("min", "max")))) (use either shp OR extent; if neither is specified global raster is returned).
transport_type: Either "walking" (default) or "motorized".
export: TRUE/FALSE Should output be saved?
output_dir: String to output folder location.