rem.glm: Iterative offset model fitting of mark-recapture with removal...

In mrds: Mark-Recapture Distance Sampling

Iterative offset model fitting of mark-recapture with removal model

Description

Detection function fitting from mark-recapture data with a removal configuration in which a secondary observer knows what the primary observer detects and detects objects missed by the primary observer. The iterative offset glm/gam uses an offset to compensate for the conditioning on the set of objects seen by either observer (eg 00 those missed by both observers are not included in the analysis. This function is similar to io.glm.

Usage

rem.glm(
  datavec,
  fitformula,
  eps = 1e-05,
  iterlimit = 500,
  GAM = FALSE,
  gamplot = TRUE,
  datavec2
)

Arguments

datavec	dataframe containing records seen by either observer 1 or 2
fitformula	logit link formula
eps	convergence criterion
iterlimit	maximum number of iterations allowed
GAM	uses GAM instead of GLM for fitting
gamplot	set to TRUE to get a gam plot object if GAM=TRUE
datavec2	dataframe containing all records for observer 1 and observer 2 as in io.glm form; this is used in case there is an observer(not platform effect)

Details

The only difference between this function and io.glm is the offset and the data construction because there is only one detection function being estimated for the primary observer. The two functions could be merged.

Value

list of class("remglm","glm","lm") or class("remglm","gam")

glmobj	GLM or GAM object
offsetvalue	offsetvalues from iterative fit
plotobj	gam plot object (if GAM & gamplot==TRUE, else NULL)

Note

currently the code in this function for GAMs has been commented out until the remainder of the mrds package will work with GAMs.

Author(s)

Jeff Laake

References

Buckland, S.T., J.M. breiwick, K.L. Cattanach, and J.L. Laake. 1993. Estimated population size of the California gray whale. Marine Mammal Science, 9:235-249.

Burnham, K.P., S.T. Buckland, J.L. Laake, D.L. Borchers, T.A. Marques, J.R.B. Bishop, and L. Thomas. 2004. Further topics in distance sampling. pp: 360-363. In: Advanced Distance Sampling, eds. S.T. Buckland, D.R.Anderson, K.P. Burnham, J.L. Laake, D.L. Borchers, and L. Thomas. Oxford University Press.

mrds documentation built on May 29, 2024, 3:56 a.m.