Generate maps for 'mapscanner' use

Generate a map image for a specified area or bounding box, by downloading tiles from https://www.mapbox.com/. Map is automatically saved in both .pdf and .png formats, by default in current working directory, or alternative location when mapname includes the full path.

Usage

ms_generate_map(
  bbox,
  max_tiles = 16L,
  mapname = NULL,
  bw = TRUE,
  style = "light",
  raster_brick = NULL
)

Arguments

bbox

Either a string specifying the location, or a numeric bounding box as a single vector of (xmin, ymin, xmax, ymax), or a 2-by-2 matrix with columns of (min, max) and rows of (x, y), respectively.

max_tiles

Maximum number of tiles to use to create map

mapname

Name of map to be produced, optionally including full path. Extension will be ignored.

bw

If FALSE, print maps in colour, otherwise black-and-white. Note that the default style = "light" is monochrome, and that this parameter only has effect for style values of "streets" or "outdoors".

style

The style of the map to be generated; one of 'light', 'streets', or 'outdoors', rendered in black and white. See https://docs.mapbox.com/api/maps/#styles/ for examples.

raster_brick

Instead of automatically downloading tiles within a given bbox, a pre-downloaded raster::rasterBrick object may be submitted and used to generate the .pdf and .png equivalents.

Value

Invisibly returns a rasterBrick object from the raster

package containing all data used to generate the map.

Examples

if (FALSE) {
# code used to generate internal files for a portion of Omaha:
bb <- osmdata::getbb ("omaha nebraska")
shrink <- 0.3 # shrink that bb to 30% size
bb <- t (apply (bb, 1, function (i) {
    mean (i) + c (-shrink, shrink) * diff (i) / 2
}))
ms_generate_map (bb, max_tiles = 16L, mapname = "omaha")
}