ggOceanMaps (version 2.2.0)

get_depth: Extract depth for coordinates from a raster bathymetry dataset

Description

Extracts depth from basemap bathymetry raster dataset for coordinates in a data frame

Usage

get_depth(
  data,
  bathy.style = "raster_continuous",
  lon = NULL,
  lat = NULL,
  shapefile = "DecimalDegree",
  proj.in = 4326,
  bind = TRUE,
  depth.col = "depth",
  verbose = FALSE
)

Value

Returns a vector if bind = FALSE, otherwise a data frame. The depths are given in a new column defined by the dist.col argument. The distances are kilometers. NA distance means that the position is on land.

Arguments

data

Data frame or sf object containing geographic coordinates.

bathy.style

Character defining the basemap bathymetry raster which should be used for the depth extraction. Valid alternatives: "raster_binned" (or "rb"), "raster_continuous" (or "rc"; default), or "raster_user" (or "ru").

lon, lat

Either the names of the longitude and latitude columns in data or NULL to guess the longitude and/or latitude columns in data.

shapefile

Land shape to which distances should be calculated. Either a character argument referring to a name of pre-made shapefiles in shapefile_list, a single sf or sp polygons object object or NULL to enable automatic definition of the land shapes based on data. Set to "DecimalDegree" by default which enables great circle distances using s2 features assuming a spherical Earth (as a contrast to earlier versions of the function which used flat Earth).

proj.in

coordinate reference system of data.

bind

Logical indicating whether x should be returned with the distances (TRUE, default) or should the distances be returned as vector (FALSE).

depth.col

The name of the depth column, if bind = TRUE. Defaults to "depth".

verbose

Logical indicating whether information about the process should be returned as messages. Set to FALSE to make the function silent.

Author

Mikko Vihtakari

Details

Uses the st_extract function to extract values from basemap bathymetry raster grids. Does not work for vector bathymetries.

Examples

if (FALSE) {
dt <- data.frame(lon = seq(-20, 80, length.out = 41), lat = 50:90)
dt <- get_depth(dt)
qmap(dt, color = depth) + scale_color_viridis_c()
}