Co-variance matrix for dream() fit

Define generic vcov() for result of lmFit() and dream()

Usage

# S4 method for MArrayLM
vcov(object, vobj, coef)

Arguments

object

MArrayLM object return by lmFit() or dream()

vobj

EList object returned by voom()

coef

name of coefficient to be extracted

Value

variance-covariance matrix