make_anglers {AnglerCreelSurveySimulation}

Create a population of anglers.

Description

Creates a population of n_anglers with trip length and fishing day length provided by the user.

Usage

make_anglers(
  n_anglers = 100,
  mean_trip_length = 3.88,
  fishing_day_length = 12,
  scale = 1
)

Arguments

n_anglers

The number of anglers in the population

mean_trip_length

The mean trip length to be used in the function. 3.88 is the default. The default is from data from the 2008 Lake Roosevelt (WA) Fishing Evaluation Program.

fishing_day_length

The fishing day length to be used in the function. Anglers are not be allowed to be fishing past this day length. The default here is set to 12 hours, which may not be a suitable day length for fisheries at higher latitudes (i.e., sunrise-sunset is > 12 hours) or during shorter seasons.

scale

The scale parameter must be positive and is passed to the rgamma function to randomly generate angler trip lengths

Details

All trip lengths will be limited so that anglers have finished their fishing trip by the end of the fishing day. The function uses a while loop to ensure that the number of anglers = n_anglers provided in the function argument. fishing_day_length is passed to the argument. The default is set to 12 hours.

starttimes are assigned by the uniform (runif) distribution

triplengths are assigned by the gamma distribution where the default mean value comes from the 2008 Lake Roosevelt Fisheries Evaluation Program data.

Value

A data frame called that includes variables start_time, trip_length, and departure_time. Summing the trip_length field returns the true fishing effort.

Author(s)

Steven H. Ranney

Examples

make_anglers(100, mean_trip_length = 4, fishing_day_length = 10)
#make_anglers(10000)