Description Usage Arguments Value See Also Examples
Indices are obtained by dividing the modelled or imputed time totals by a reference value. Most commonly, the time totals for the first time point are used as reference. As a result, the index value for this first time point will be 1.0, with a standard error of 0.0 by definition. Alternatively, a range of time points can be used as reference. In this case, the mean time totals for this range will be used as reference, and the standard errors will be larger than 0.0.
1 2 3 4 5 6 7 |
x |
an object of class |
which |
|
covars |
|
base |
|
level |
|
A data frame containing indices and their uncertainty expressed as
standard error. Depending on the chosen output, columns fitted
and se_fit
, and/or imputed
and se_imp
are present.
If covars
is TRUE
, additional indices are computed for the
individual covariate categories. In this case additional columns
covariate
and category
are present. The overall indices are
marked as covariate ‘Overall’ and category 0.
Other analyses:
coef.trim()
,
confint.trim()
,
gof()
,
now_what()
,
overall()
,
overdispersion()
,
plot.trim.index()
,
plot.trim.overall()
,
results()
,
serial_correlation()
,
summary.trim()
,
totals()
,
trim()
,
vcov.trim()
,
wald()
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 | data(skylark)
z <- trim(count ~ site + time, data=skylark, model=2)
index(z)
# mimic classic TRIM:
index(z, "both")
# Extract standard errors for the imputed data
SE <- index(z,"imputed")$se_mod
# Include covariates
skylark$Habitat <- factor(skylark$Habitat) # hack
z <- trim(count ~ site + time + Habitat, data=skylark, model=2)
ind <- index(z, covars=TRUE)
plot(ind)
# Use alternative base year
index(z, base=3)
# Use average of first 5 years as reference for indexing
index(z, base=1:5)
|
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