secr (version 2.0.0)

traps: Detector Array

Description

An object of class traps encapsulates a set of detector (trap) locations and related data. A method of the same name extracts or replaces the traps attribute of a capthist object.

Usage

traps(object, ...)
traps(object) <- value

Arguments

object

a capthist object.

value

traps object to replace previous.

...

other arguments (not used).

Details

An object of class traps holds detector (trap) locations as a data frame of x-y coordinates. Trap identifiers are used as row names. The required attribute `detector' records the type of detector (`single', `multi' or `proximity' etc.; see detector for more). Other possible attributes of a traps object are average spacing, trap-specific covariates (covariates), and a matrix of binary (0/1) codes indicating whether each detector was used on each occasion (usage). If usage is specified, at least one detector must be `used' on each occasion.

References

Efford, M. G. (2007) Density 4.1: software for spatially explicit capture--recapture. Department of Zoology, University of Otago, Dunedin, New Zealand. http://www.otago.ac.nz/density Efford, M. G., Borchers D. L. and Byrom, A. E. (2009) Density estimation by spatially explicit capture-recapture: likelihood-based methods. In: D. L. Thomson, E. G. Cooch and M. J. Conroy (eds) Modeling Demographic Processes in Marked Populations. Springer, New York. Pp. 255--269.

See Also

make.grid, read.traps, plot.traps, secr.fit, spacing, detector

Examples

demotraps <- make.grid(nx = 8, ny = 6, spacing = 30)
demotraps    ## uses print method for traps
summary (demotraps)

plot (demotraps, border = 50, label = TRUE, offset = 8, 
    gridlines=FALSE)  

## generate an arbitrary covariate 'randcov'
covariates (demotraps) <- data.frame(randcov = rnorm(48))

## overplot detectors that have high covariate values
temptr <- subset(demotraps, covariates(demotraps)$randcov > 0.5)
plot (temptr, add = TRUE, 
    detpar = list (pch = 16, col = 'green', cex = 2))