Extract and/or plot bathymetry data from a NetCDF file downloaded by FjordLight
.
flget_bathymetry.Rd
This functions will conveniently extract the bathymetry data stored within a
NetCDF file downloaded via fl_DownloadFjord
. There are options
for how the user would like to subset the data, which data format the data
should be extracted to, and if the user would like to plot the data in the process.
Arguments
- fjord
Expects the object loaded via
fl_LoadFjord
.- what
The default value
"o"
will load all "ocean" data, meaning it will filter out any land pixels. The other options are:"c"
filters out only coastal bathymetry data (depth of 200 m to 0 m),"s"
filters out only shallow bathymetry data (depth of 50 m to 0 m), and"l"
loads only the land data. One may combine"o"
,"c"
, or"s"
, with"l"
(e.g."ol"
) to load both sea and land data.- mode
Determines the format of the bathymetry data loaded into the R environment. The default
"raster"
will load the data as a raster format. The other option"df"
will load the data as a data.frame with three columns.- PLOT
Boolean argument (default =
FALSE
) that tells the function if the user would like the loaded bathymetry and/or elevation data to be plotted or not. NB: this argument will only run if the user choosesmode = "raster"
.
Value
Depending on which arguments the user chooses, this function will return the
filtered bathymetry data as a RasterLayer
(mode = "raster"
) or
data.frame (mode = "df"
). The data.frame will contain the following columns:
- longitude
degree decimals
- latitude
degree decimals
- depth
metres
Note that the depth column will contain both elevation (positive) and depth (negative) values.
Examples
# Load data
fjord_code <- "test"
fjorddata <- fl_LoadFjord(fjord_code, dirdata = system.file("extdata", package = "FjordLight"))
# Shallow data (what = "s"; s for shallow) as a data.frame
shallow_df <- flget_bathymetry(fjorddata, what = "s", mode = "df")
# Plot all ocean and land data
# \donttest{
full_bathy <- flget_bathymetry(fjorddata, what = "ol", mode = "raster", PLOT = TRUE)
# }
# Plot only land data
# \donttest{
land_only <- flget_bathymetry(fjorddata, what = "l", mode = "raster", PLOT =TRUE)
# }
# For more examples see: https://face-it-project.github.io/FjordLight/articles/fl_example.html