Internal method that creates linear fits
lm_robust_fit(y, X, weights, cluster, ci, se_type, has_int, alpha = 0.05,
return_vcov = TRUE, return_fit = FALSE, return_unweighted_fit = FALSE,
try_cholesky = FALSE, X_first_stage = NULL)
numeric outcome vector
numeric design matrix
numeric weights vector
numeric cluster vector
boolean that when T returns confidence intervals and p-values
character denoting which kind of SEs to return
logical, whether the model has an intercept, used for \(R^2\)
numeric denoting the test size for confidence intervals
logical, whether to return the vcov matrix for later usage
logical, whether to return fitted values
logical, whether to return unweighted fitted values in place of weighted fitted values if regression is weighted
logical, whether to try using a cholesky decomposition to solve LS instead of a QR decomposition
numeric matrix of the first stage design matrix, only use for second stage of 2SLS IV regression, otherwise leave as NULL