Stratified-Petersen Analysis System
R package SPAS version 2019.2
The Stratified-Petersen Analysis System (SPAS) is designed
to estimate abundance in two-sample capture-recapture experiments
where the capture and recaptures are stratified. This is a generalization
of the simple Lincoln-Petersen estimator.
Strata may be defined in time or in space or both,
and the s strata in which marking takes place
may differ from the t strata in which recoveries take place.
When s=t, SPAS reduces to the method described by
Darroch (1961) <https://www.jstor.org/stable/2332748>.
When s<t, SPAS implements the methods described in
Plante, Rivest, and Tremblay (1988)
<https://www.jstor.org/stable/2533994>.
Schwarz and Taylor (1998) <doi:10.1139/f97-238> describe
the use of SPAS in estimating return of salmon stratified by
time and geography.
A related package, BTSPAS, deals with temporal stratification where
a spline is used to model the distribution of the population
over time as it passes the second capture location.
This is the R-version of the (now obsolete) standalone Windows
program available at <http://www.cs.umanitoba.ca/~popan/spas/spas_home.html>.
Software
Imports: BB, MASS, Matrix, msm, numDeriv, plyr
Suggests: knitr, rmarkdown
Carl James Schwarz <cschwarz.stat.sfu.ca@gmail.com>
Comprehensive R Archive Network (CRAN)
Carl James Schwarz
GPL (>= 2)
2019-02-18
application/tgz
https://CRAN.R-project.org/package=SPAS