Plot a ppi on a Stamen Maps, OpenStreetMap, Google Maps or Naver Map base layer map using ggmap.
map(x, ...)
# S3 method for ppi
map(
x,
map,
param,
alpha = 0.7,
xlim,
ylim,
zlim = c(-20, 20),
ratio,
radar_size = 3,
radar_color = "red",
n_color = 1000,
radar.size = 3,
radar.color = "red",
n.color = 1000,
palette = NA,
...
)
An object of class ppi
.
Arguments passed to low level ggmap function.
The basemap to use, result of a call to download_basemap.
The scan parameter to plot.
Transparency of the data, value between 0 and 1.
Range of x values to plot (degrees longitude), as atomic vector of length 2.
Range of y values to plot (degrees latitude), as an atomic vector of length 2.
The range of values to plot.
Aspect ratio between x and y scale, by default \(1/cos(latitude radar * pi/180)\).
Size of the symbol indicating the radar position.
Color of the symbol indicating the radar position.
The number of colors (>=1) to be in the palette.
Deprecated argument, use radar_size instead.
Deprecated argument, use radar_color instead.
Deprecated argument, use n_color instead.
(Optional) character vector of hexadecimal color values defining the plot color scale, e.g. output from viridis
A ggmap object (a classed raster object with a bounding box attribute).
Available scan parameters for mapping can by printed to screen by
summary(x)
. Commonly available parameters are:
DBZH
", "DBZ
"(Logged) reflectivity factor (dBZ)
TH
", "T
"(Logged) uncorrected reflectivity factor (dBZ)
VRADH
", "VRAD
"Radial velocity (m/s). Radial velocities towards the radar are negative, while radial velocities away from the radar are positive
RHOHV
"Correlation coefficient (unitless) Correlation between vertically polarized and horizontally polarized reflectivity factor
PHIDP
"Differential phase (degrees)
ZDR
"(Logged) differential reflectivity (dB)
The scan parameters are named according to the OPERA data information model (ODIM), see Table 16 in the ODIM specification.
map(ppi)
: plot a 'ppi' object on a map
# load an example scan:
data(example_scan)
# make ppi's for all scan parameters in the scan
ppi <- project_as_ppi(example_scan)
#> Warning: CRS object has comment, which is lost in output; in tests, see
#> https://cran.r-project.org/web/packages/sp/vignettes/CRS_warnings.html
# \dontrun{
# grab a basemap that matches the extent of the ppi:
# using a gray-scale basemap:
basemap <- download_basemap(ppi, maptype = "toner-lite")
#> Downloading zoom = 9 ...
#> Map tiles by Stamen Design, under CC BY 3.0. Data by OpenStreetMap, under ODbL.
# map the radial velocity scan parameter onto the basemap:
map(ppi, map = basemap, param = "VRADH")
#> Warning: CRS object has comment, which is lost in output; in tests, see
#> https://cran.r-project.org/web/packages/sp/vignettes/CRS_warnings.html
# extend the plotting range of velocities, from -50 to 50 m/s:
map(ppi, map = basemap, param = "VRADH", zlim = c(-50, 50))
#> Warning: CRS object has comment, which is lost in output; in tests, see
#> https://cran.r-project.org/web/packages/sp/vignettes/CRS_warnings.html
# map the reflectivity on a terrain basemap:
basemap <- download_basemap(ppi, maptype = "terrain")
#> Downloading zoom = 9 ...
#> Map tiles by Stamen Design, under CC BY 3.0. Data by OpenStreetMap, under ODbL.
map(ppi, map = basemap, param = "DBZH")
#> Warning: CRS object has comment, which is lost in output; in tests, see
#> https://cran.r-project.org/web/packages/sp/vignettes/CRS_warnings.html
# change the color palette, e.g. Viridis colors:
map(ppi, map = basemap, param = "DBZH", palette = viridis::viridis(100), zlim=c(-10,10))
#> Warning: CRS object has comment, which is lost in output; in tests, see
#> https://cran.r-project.org/web/packages/sp/vignettes/CRS_warnings.html
# give the data more transparency:
map(ppi, map = basemap, param = "DBZH", alpha = 0.3)
#> Warning: CRS object has comment, which is lost in output; in tests, see
#> https://cran.r-project.org/web/packages/sp/vignettes/CRS_warnings.html
# change the appearance of the symbol indicating the radar location:
map(ppi, map = basemap, radar_size = 5, radar_color = "blue")
#> Warning: CRS object has comment, which is lost in output; in tests, see
#> https://cran.r-project.org/web/packages/sp/vignettes/CRS_warnings.html
# crop the map:
map(ppi, map = basemap, xlim = c(12.4, 13.2), ylim = c(56, 56.5))
#> Warning: CRS object has comment, which is lost in output; in tests, see
#> https://cran.r-project.org/web/packages/sp/vignettes/CRS_warnings.html
#> Warning: Removed 1 rows containing missing values (geom_rect).
# }