warning('Some estimated standard deviations are negative. Dynare internally works with variances so that the sign does not matter. Nevertheless, it is recommended to impose either prior restrictions (Bayesian Estimation) or a lower bound (ML) to assure positive values.')
warning(sprintf('Some estimated standard deviations are negative.\n Dynare internally works with variances so that the sign does not matter.\n Nevertheless, it is recommended to impose either prior restrictions (Bayesian Estimation)\n or a lower bound (ML) to assure positive values.'))