| subset.capthist {secr} | R Documentation |
Create a new capthist object or list of objects by selecting rows (individuals), columns (occasions) and traps from an existing capthist object.
## S3 method for class 'capthist':
subset(x, subset = NULL, occasions = NULL, traps = NULL,
sessions = NULL, cutval = NULL, dropnull = TRUE, dropunused = TRUE,
renumber = FALSE, ...)
## S3 method for class 'capthist':
split(x, f, drop = FALSE, prefix = 'S', ...)
x |
object of class capthist |
subset |
vector of subscripts to select rows (individuals) |
occasions |
vector of subscripts to select columns (occasions) |
traps |
vector of subscripts to select detectors (traps) |
sessions |
vector of subscripts to select sessions |
cutval |
new threshold for signal strength |
dropnull |
logical for whether null (all-zero) capture histories should be dropped |
dropunused |
logical for whether never-used detectors should be dropped |
renumber |
logical for whether row.names should be replaced with sequence number in new capthist |
f |
factor or object that may be coerced to a factor |
drop |
logical indicating if levels that do not occur should be dropped (if f is a factor) |
prefix |
a character prefix to be used for component names when values of f are numeric |
... |
other arguments (not used currently) |
Subscript vectors may be either logical (length equal to the relevant
dimension of x) or integer-valued. Subsetting is applied to
attributes (e.g. covariates, traps) as appropriate. The
default action is to include all rows, columns and traps if the relevant
argument is omitted.
When traps is provided, detections at other detectors are set to
zero, as if the detector had not been used, and the corresponding rows
are removed from traps. If the detector type is 'proximity' then
selecting traps also reduces the third dimension of the capthist array.
split generates a list in which each component is a
capthist object. Each component corresponds to a level of
f.
To combine (pool) occasions use reduce.capthist. There is
no equivalent of unlist for lists of capthist objects.
capthist object with the requested subset of observations, or a
list of such objects (i.e., a multi-session capthist object).
List input results in list output, except when a single session is
selected.
Murray Efford murray.efford@otago.ac.nz
capthist, rbind.capthist, reduce.capthist
tempcapt <- sim.capthist (make.grid(nx=6, ny=6), nocc=6)
summary(subset(tempcapt, occ=c(1,3,5)))
## Consider 'proximity' detections at a random subset of detectors
## This would not make sense for 'multi' detectors, as the
## excluded detectors influence detection probabilities in
## sim.capthist.
tempcapt2 <- sim.capthist (make.grid(nx = 6, ny = 6,
detector = 'proximity'), nocc = 6)
tempcapt3 <- subset(tempcapt2, traps = sample(1:36, 18,
replace=FALSE))
summary(tempcapt3)
plot(tempcapt3)
split (tempcapt2, f = sample (c('A','B'), nrow(tempcapt2),
replace = TRUE))