R package lmvar. Linear Regression with Non-Constant Variances. Runs a linear regression in which both the expected value and the variance can vary per observation. The expected values mu follows the standard linear model mu = X_mu * beta_mu. The standard deviation sigma follows the model log(sigma) = X_sigma * beta_sigma. The package comes with two vignettes: ’Intro’ gives an introduction, ’Math’ gives mathematical details.