SHARK4R (version 1.0.2)

lookup_xy: Lookup spatial information for geographic points

Description

Retrieves shore distance, environmental grids, and area values for given coordinates. Coordinates may be supplied either through a data frame or as separate numeric vectors.

Usage

lookup_xy(
  data = NULL,
  lon = NULL,
  lat = NULL,
  shoredistance = TRUE,
  grids = TRUE,
  areas = FALSE,
  as_data_frame = TRUE
)

Value

A data frame or list, depending on as_data_frame. Invalid coordinates produce NA entries (data frame) or NULL elements (list). Duplicate input coordinates return repeated results.

Arguments

data

Optional data frame containing coordinate columns. The expected names are sample_longitude_dd and sample_latitude_dd. These must be numeric and fall within valid geographic ranges.

lon

Optional numeric vector of longitudes. Must be supplied together with lat when used. Ignored when a data frame is provided unless both lon and lat are set.

lat

Optional numeric vector of latitudes. Must be supplied together with lon when used.

shoredistance

Logical; if TRUE, distance to the nearest shore is included.

grids

Logical; if TRUE, environmental grid values are included.

areas

Logical or numeric. When logical, TRUE requests area values at zero radius, and FALSE disables area retrieval. A positive integer specifies the search radius in meters for area values.

as_data_frame

Logical; if TRUE, the result is returned as a data frame. When FALSE, the result is returned as a list.

Details

• When both vector inputs and a data frame are provided, the vector inputs take precedence.

• Coordinates are validated and cleaned before lookup, and only unique values are queried.

• Queries are processed in batches to avoid overloading the remote service.

• Area retrieval accepts either a logical flag or a radius. A radius of zero corresponds to requesting a single area value.

• Final results are reordered to match the original input positions.

• The function has been modified from the obistools package (Provoost and Bosch, 2024).

References

Provoost P, Bosch S (2024). “obistools: Tools for data enhancement and quality control” Ocean Biodiversity Information System. Intergovernmental Oceanographic Commission of UNESCO. R package version 0.1.0, https://iobis.github.io/obistools/.

See Also

check_onland, check_depth, https://iobis.github.io/xylookup/ – OBIS xylookup web service

Examples

# \donttest{
# Using a data frame
df <- data.frame(sample_longitude_dd = c(10.9, 18.3),
                 sample_latitude_dd = c(58.1, 58.3))
lookup_xy(df)

# Area search within a radius
lookup_xy(df, areas = 500)

# Using separate coordinate vectors
lookup_xy(lon = c(10.9, 18.3), lat = c(58.1, 58.3))
# }