Extract variance-covariance of residuals 'Sigma'

Extract the variance-covariance matrix of the residuals, usually noted \(\Sigma\) in ZIPLN models.

Usage

# S3 method for class 'ZIPLNfit'
sigma(object, ...)

Arguments

object

an R6 object with class ZIPLNfit

...

additional parameters for S3 compatibility. Not used

Value

A semi definite positive matrix of size p, assuming there are p species in the model.

See also

coef.ZIPLNfit()