bioRad (version 0.5.1)

download_basemap: Download a basemap for map(ppi)

Description

Downloads a Stamen Maps or Google Maps base layer map using get_map.

Usage

download_basemap(
  x,
  verbose = TRUE,
  zoom,
  alpha = 1,
  source = "stamen",
  maptype = "terrain",
  ...
)

Arguments

x

An object of class ppi.

verbose

Logical, whether to print information to console.

zoom

Zoom level (optional), see get_map. An integer from 3 (continent) to 21 (building). By default the zoom level matching the ppi extent is selected automatically.

alpha

Transparency of the basemap (0-1).

source

String identifying which map service should be used: "stamen" or "google".

maptype

Type of basemap to plot. For Stamen Maps: "terrain", "terrain-background", "terrain-labels", "terrain-lines", "toner", "toner-2010", "toner-2011", "toner-background", "toner-hybrid", "toner-labels", "toner-lines", "toner-lite", "watercolor". For Google Maps: "terrain", "satellite", "roadmap", "hybrid"

...

Arguments to pass to get_map function.

Details

To use Google Maps as source, you will have to register with Google, enable billing and provide an API key to ggmap. See the ggmap README for details.

To use maptype, install the development version of ggmap (>3.0.0) with devtools::install_github("dkahle/ggmap").

Examples

# NOT RUN {
# load an example scan:
data(example_scan)

# print summary info for the scan:
example_scan

# make ppi for the scan
ppi <- project_as_ppi(example_scan)
# }
# NOT RUN {
# grab a basemap that matches the extent of the ppi:
basemap <- download_basemap(ppi)

# map the reflectivity quantity of the ppi onto the basemap:
map(ppi, map = basemap, param = "DBZH")

# increase the transparancy of the basemap:
basemap <- download_basemap(ppi, alpha = 0.3)
map(ppi, map = basemap, param = "DBZH")

# download a different type of basemap, e.g. a gray-scale image:
# see get_map() in ggmap library for full documentation of options
basemap <- download_basemap(ppi, maptype = "toner-lite")

# map the radial velocities onto the line image:
map(ppi, map = basemap, param = "VRADH")
# }