Returns a 2-by-n matrix of estimating equation contributions for the mean and variance: $$\psi_i(\theta) = \begin{pmatrix} Y_i - \theta_1 \\ (Y_i - \theta_1)^2 - \theta_2 \end{pmatrix}$$
Examples
y <- c(1, 2, 3, 1, 4, 5, 3, 2, 6, 7)
psi <- function(theta) ee_mean_variance(theta, y = y)
m <- m_estimate(stacked_equations = psi, init = c(0, 1))
coef(m)
#> mean variance
#> 3.40 3.84