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Determine if Points are in a Specified Sea Basin

Source: R/ifcb_which_basin.R
ifcb_which_basin.Rd

This function identifies which sub-basin a set of latitude and longitude points belong to, using a user-specified or default shapefile. The default shapefile includes the Baltic Sea, Kattegat, and Skagerrak basins and is included in the iRfcb package.

Usage

ifcb_which_basin(latitudes, longitudes, plot = FALSE, shape_file = NULL)

Arguments

latitudes

A numeric vector of latitude points.

longitudes

A numeric vector of longitude points.

plot

A boolean indicating whether to plot the points along with the sea basins. Default is FALSE.

shape_file

The absolute path to a custom polygon shapefile in WGS84 (EPSG:4326) that represents the sea basin. Defaults to the Baltic Sea, Kattegat, and Skagerrak basins included in the iRfcb package.

Value

A vector indicating the basin each point belongs to, or a ggplot object if plot = TRUE.

Details

This function reads a pre-packaged shapefile of the Baltic Sea, Kattegat, and Skagerrak basins from the iRfcb package by default, or a user-supplied shapefile if provided. The shapefiles originate from SHARK (https://shark.smhi.se/). It sets the CRS, transforms the CRS to WGS84 (EPSG:4326) if necessary, and checks if the given points fall within the specified sea basin. Optionally, it plots the points and the sea basin polygons together.

Examples

# Define example latitude and longitude vectors
latitudes <- c(55.337, 54.729, 56.311, 57.975)
longitudes <- c(12.674, 14.643, 12.237, 10.637)

# Check in which Baltic sea basin the points are in
points_in_the_baltic <- ifcb_which_basin(latitudes, longitudes)
print(points_in_the_baltic)
#> [1] "13 - Arkona Basin"   "12 - Bornholm Basin" "16 - Kattegat"      
#> [4] "17 - Skagerrak"     

# Plot the points and the basins
ifcb_which_basin(latitudes, longitudes, plot = TRUE)