Retrieves topographic data from ETOPO1 Global Relief Model (see references).
GetTopography(
lon.west,
lon.east,
lat.north,
lat.south,
resolution = 3.5,
cache = TRUE,
file.dir = tempdir(),
verbose = interactive()
)latitudes and longitudes of the bounding box in degrees
numeric vector indicating the desired resolution (in degrees) in the lon and lat directions (maximum resolution is 1 minute)
logical indicating if the results should be saved on disk
optional directory where to save and/or retrieve data
logical indicating whether to print progress
A data table with height (in meters) for each longitude and latitude.
Very large requests can take long and can be denied by the NOAA server. If the function fails, try with a smaller bounding box or coarser resolution.
Longitude coordinates must be between 0 and 360.
Source: Amante, C. and B.W. Eakins, 2009. ETOPO1 1 Arc-Minute Global Relief Model: Procedures, Data Sources and Analysis. NOAA Technical Memorandum NESDIS NGDC-24. National Geophysical Data Center, NOAA. doi:10.7289/V5C8276M
if (FALSE) { # \dontrun{
topo <- GetTopography(280, 330, 0, -60, resolution = 0.5)
library(ggplot2)
ggplot(topo, aes(lon, lat)) +
geom_raster(aes(fill = h)) +
geom_contour(aes(z = h), breaks = 0, color = "black", size = 0.3) +
scale_fill_gradient2(low = "steelblue", high = "goldenrod2", mid = "olivedrab") +
coord_quickmap()
} # }