R: Extract variance-covariance of residuals 'Sigma'

sigma.PLNfit {PLNmodels} | R Documentation

## Extract variance-covariance of residuals 'Sigma'

### Description

Extract the variance-covariance matrix of the residuals, usually noted

Σ

in PLN models. This captures the correlation between the species in the latent space.

### Usage

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

### Arguments

`object` | an R6 object with class `PLNfit`
`...` | 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.PLNfit()`, `standard_error.PLNfit()` and `vcov.PLNfit()` for other ways to access

Σ

.

### Examples

    data(trichoptera)
    trichoptera <- prepare_data(trichoptera$Abundance, trichoptera$Covariate)
    myPLN <- PLN(Abundance ~ 1 + offset(log(Offset)), data = trichoptera)
    sigma(myPLN) ## Sigma

[Package PLNmodels version 0.11.6 Index]