vcov.trim {rtrim}

Extract variance-covariance matrix from TRIM output

Description

Extract variance-covariance matrix from TRIM output

Usage

## S3 method for class 'trim'
vcov(object, which = c("imputed", "fitted"), ...)

Arguments

object

TRIM output structure (i.e., output of a call to trim)

which

[character] Selector to distinguish between variance-covariance based on the imputed counts (default), or the fitted counts.

...

Arguments to pass to or from other methods (currently unused; included for consistency with vcov).

Value

a J x J matrix, where J is the number of years (or time-points).

See Also

Other analyses: coef.trim(), confint.trim(), gof(), index(), now_what(), overall(), overdispersion(), plot.trim.index(), plot.trim.overall(), plot.trim.smooth(), results(), serial_correlation(), summary.trim(), totals(), trendlines(), trim(), wald()

Examples

data(skylark)
z <- trim(count ~ site + time, data=skylark, model=3);
totals(z)
vcv1 <- vcov(z)          # Use imputed data
vcv2 <- vcov(z,"fitted") # Use fitted data