This function tries to download the aerial orthophoto of the requested
domain from the
Italian National Geoportal.
The output is given in png format at the path given in the file
parameter.
Usage
downloadBasemap(
file = file,
xSW = 410000,
ySW = 5000500,
xExt = 5000,
yExt = 5000,
crs = 32,
width = 1024,
height = 1024,
units = "px",
res = 72
)
Arguments
- file
Path to output file.
- xSW
South West Easting UTM coordinate of the basemap (in metres).
- ySW
South West Northing UTM coordinate of the basemap (in metres).
- xExt
Easting extension in metres.
- yExt
Northing extension in metres.
- crs
UTM Coordinate Reference System: either 32 or 33.
- width
The basemap width.
- height
The basemap height.
- units
The unit of measure of width and height. It can be
px
(pixels, the default),in
(inches),cm
ormm
- res
The resolution in dpi.
Examples
if (FALSE) {
# Download a basemap of a domain with SW coordinates (410000, 5000500)
# in the UTM32 CRS and extension 5000m in both directions.
downloadBasemap(file = "./basemap.png",
xSW = 410000, ySW = 5000500, xExt = 5000, yExt = 5000)
# Download a basemap of a domain with SW coordinates (410000, 5000500)
# in the UTM32 CRS and extension 5000m in both directions.
# The file has to be 2048 x 2048 pixels.
downloadBasemap(file = "./basemap.png",
xSW = 410000, ySW = 5000500, xExt = 5000, yExt = 5000,
width = 2048, height = 2048)
# Download a basemap of a domain with SW coordinates (410000, 5000500)
# in the UTM32 CRS and extension 5000m in both directions.
# The file has to be 10cm x 10cm with a resolution of 150 dpi.
downloadBasemap(file = "./basemap.png",
xSW = 410000, ySW = 5000500, xExt = 5000, yExt = 5000,
width = 10, height = 10, units = "cm", res = 150)
}