Given a model object, this function computes population sizes given thresholds for a state variable of interest. For example, the number (or proportion) of individuals shorter than 60 cm tall at the 20th time step of the model.
collapse_pop_state(ipm, time_step, ...)An object created by make_ipm
the time step to pull out. Can be a single time step or a vector of multiple time steps. In the latter case, one value is computed for each time step.
Named expressions that provide the threshold information for the desired classes. The expression should be logicals with a state variable name on the left side, and a threshold value on the right side.
A named list of numeric vectors containing the summed population
sizes at each requested time step. Names are taken from ....
data(gen_di_det_ex)
# Rebuild the model and return_main_env this time
gen_di_det_ex <- gen_di_det_ex$proto_ipm %>%
make_ipm(iterate = TRUE, iterations = 50, return_main_env = TRUE)
disc_sizes <- collapse_pop_state(gen_di_det_ex,
time_step = 20:25,
seedlings = ht <= 10,
NRA = ht > 10 & ht <= 200,
RA = ht > 200)