collated_index compute a collated index from the site indices, using a Generalized Linear Model.

collated_index(
  data,
  s_sp,
  sindex_value = "SINDEX",
  bootID = NULL,
  boot_ind = NULL,
  glm_weights = TRUE,
  rm_zero = TRUE
)

Arguments

data: data.table or data.frame Site indices per year and proportion of flight curve covered by the monitoring.
s_sp: string Species name to be found in the data.
sindex_value: string Name of the response variable to be used the computation of the collated index, default is "SINDEX", but could be other standardized values.
bootID: integer Identify the n^th bootstrap.
boot_ind: data.table Index of the bootstrap and the site ids of the specific bootstrap sample.
glm_weights: logical Use the proportion of the flight curve sampled as weight for the collated index, if FALSE the function uses equal weights.
rm_zero: logical Remove the sites where species was not observed to speed-up the fit of the GLM without altering the output, default TRUE.

a list of two objects, a vector of site, a glm model object, and a vector of collated indices per year.