Create Previous Location/Area Variable — previous

Creates a variable of the previous port/zone (previous area) or the previous longitude/latitude for a vessel.

Usage

previous_loc(
  dat,
  spat,
  project,
  starting_port,
  v_id,
  tripID,
  haulID,
  zoneID = NULL,
  spatID = NULL,
  date = NULL,
  lon = NULL,
  lat = NULL
)

Arguments

dat: Primary data containing information on hauls or trips. Table in FishSET database contains the string 'MainDataTable'.
spat: A spatial data file containing information on fishery management or regulatory zones boundaries. sf objects are recommended, but sp objects can be used as well. See dat_to_sf() to convert a spatial table read from a csv file to an sf object. To upload your spatial data to the FishSETFolder see load_spatial().
project: String, name of project.
starting_port: The name of the starting (or disembarking) port in dat.
v_id: The name of the variable in dat that uniquely identifies vessels.
tripID: Variable name in dat that uniquely identifies trips.
haulID: Variable name in dat that uniquely identifies hauls.
zoneID: Name of zone ID column in dat. Used to identify the previous area. Required for previous area variable.
spatID: Name of zone ID column in spat. spat is used to assign ports to spatial areas. Required for previous area variable.
date: Optional, a date variable to order hauls by.
lon: Longitude variable from dat. Required for previous location variable.
lat: Latitude variable from dat. Required for previous location variable.

Details

previous_loc() can create a previous area or location variable. "Previous area" is defined as the port or zone the vessel last visited. The first area for each trip is the disembarking port (starting_port). If a port is within a zone, the zone is returned. If a port is not within a zone, the name of the port is returned. "Previous location" is defined as the previous longitude and latitude of the vessel. The first set of coordinates is the location of the port. Users must have a port table saved to the FishSET database to use this function (see load_port()). This variable can be used to define the distance matrix (see create_alternative_choice()).