Create trip centroid variable

Create latitude and longitude variables containing the centroid of each trip

Usage

create_trip_centroid(dat, project, lon, lat, tripID, weight.var = NULL)

Arguments

dat

Primary data containing information on hauls or trips. Table in the FishSET database contains the string 'MainDataTable'.

project

Project name.

lon

Variable in dat containing longitudinal data.

lat

Variable in dat containing latitudinal data.

tripID

Variable in dat containing trip identifier. If trip identifier should be defined by more than one variable then list as c('var1', 'var2').

weight.var

Variable in dat for computing the weighted average.

Value

Returns the primary dataset with centroid latitude and centroid longitude variables added.

Details

Computes the average longitude and latitude for each trip. Specify weight.var to calculate the weighted centroid. Additional arguments can be added that define unique trips. If no additional arguments are added, each row will be treated as a unique trip.

Examples

if (FALSE) {
pollockMainDataTable <- create_trip_centroid(pollockMainDataTable, 'pollock', 'LonLat_START_LON', 
  'LonLat_START_LAT', weight.var = NULL, 'DISEMBARKED_PORT', 'EMBARKED_PORT')
}