# S3 method for secr
predict(object, newdata = NULL, realnames = NULL, type = c("response", "link"),
se.fit = TRUE, alpha = 0.05, savenew = FALSE, …)# S3 method for secrlist
predict(object, newdata = NULL, realnames = NULL, type = c("response", "link"),
se.fit = TRUE, alpha = 0.05, savenew = FALSE, …)
# S3 method for secr
detectpar(object, …, byclass = FALSE)
secr
object output from secr.fit
, or list
of secr
objects (secrlist) se.fit
= FALSE, a dataframe identical to newdata
except for the addition of one column for each `real' parameter. Otherwise, a list with one component for each row in newdata
. Each component is a dataframe with one row for each `real' parameter (density, g0, sigma, b) and columns as belowlink | link function |
estimate | estimate of real parameter |
SE.estimate | standard error of the estimate |
lcl | lower 100(1--alpha)% confidence limit |
ucl | upper 100(1--alpha)% confidence limit |
When newdata
has only one row, the structure of the list is
`dissolved' and the return value is one data frame.
For detectpar
, a list with the estimated values of detection
parameters (e.g., g0 and sigma if detectfn = "halfnormal"). In the case
of multi-session data the result is a list of lists (one list per
session).
The variables in the various linear predictors are described in
secr models and listed for the particular model in the
vars
component of object
.
Optional newdata
should be a dataframe with a column for each of
the variables in the model (see `vars' component of object
). If
newdata
is missing then a dataframe is constructed automatically.
Default newdata
are for a naive animal on the first occasion;
numeric covariates are set to zero and factor covariates to their base
(first) level.
realnames
may be used to select a subset of parameters.
Standard errors for parameters on the response (real) scale are by the delta method (Lebreton et al. 1992), and confidence intervals are backtransformed from the link scale.
The value of newdata
is optionally saved as an attribute.
detectpar
is used to extract the detection parameter estimates
from a simple model to pass to functions such as
esa.plot
. detectpar
calls predict.secr
. Parameters
will be evaluated by default at base levels of the covariates, although
this may be overcome by passing a one-line newdata
to
predict
via the … argument. Groups and mixtures are a
headache for detectpar
: it merely returns the estimated detection
parameters of the first group or mixture.
If the `a0' parameterization has been used in secr.fit
(i.e.,
object$details$param == 3
) then detectpar
automatically
backtransforms (a0, sigma) to (g0, sigma) or (lambda0, sigma) depending
on the value of object$detectfn
.
secr.fit
, predictDsurface
## load previously fitted secr model with trap response
## and extract estimates of `real' parameters for both
## naive (b = 0) and previously captured (b = 1) animals
predict (secrdemo.b, newdata = data.frame(b=0:1))
temp <- predict (secrdemo.b, newdata = data.frame(b=0:1),
save = TRUE)
attr(temp, "newdata")
detectpar(secrdemo.0)
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