Create matrix of presences and absences.

Based on a given population, `create_presences()` creates a matrix of presences and absences based on a probability function to remain in the country.

Usage

create_presences(
  pop,
  varying_arrival = FALSE,
  const_rate_arrival = TRUE,
  formula_phi,
  coef_values,
  years = 2
)

Arguments

pop

A baseline population from which one will select individuals to arrive and leave in a number of years.

varying_arrival

A logical parameter that controls if all individuals arrive in the first year or not. Default is FALSE.

const_rate_arrival

In case individuals are arriving in different years, then if `TRUE` individuals will arrive at a constant rate each year. If `FALSE` then will arrive randomly in the different years.

formula_phi

A linear predictor formula to calculate the probability of leaving the country.

coef_values

The values for each coefficient to be used in the linear predictor defined in `formula_phi`. The coefficients will be used considering a logit link function.

years

Number of years to define this matrix of absences and presences.

Value

A matrix with the information of the presence (1) or absence (0) for each individual of the population considering a number of years of observation.

Examples

main_pop <- create_population(
size = 500,
n_cat_var = 3,
prob_bin = c(0.5))

# example with all individuals arriving in the first year.
presences <- create_presences(main_pop,
  formula_phi = ~ bin1,
  coef_values = c(2, -1),
  years = 3)
colSums(presences)
#> [1] 500 399 329

# example with constant rate of arrival of individuals in each year.
presences <- create_presences(main_pop,
  formula_phi = ~ bin1,
  coef_values = c(2, -1),
  varying_arrival = TRUE,
  years = 3)
colSums(presences)
#> [1] 250 454 355

# example with varying rate of arrival of individuals in each year.
presences <- create_presences(main_pop,
  formula_phi = ~ bin1,
  coef_values = c(2, -1),
  varying_arrival = TRUE,
  const_rate_arrival = FALSE,
  years = 3)
colSums(presences)
#> [1] 224 456 369