title: robustlmm function rlmer() too slow
body: <p>I want to conduct a mixed model with robust standard errors in a dataset with 45,000 rows. When I try to run the below code using rlmer() from the robustlmm package, it doesn't produce any result within 10 minutes (and probably longer). Y is continuous 1-12, x is binary, and PID is continuous 1:3000.</p>
  <pre><code>rlmer(y ~ x + (1|ID), data=dta_long)
  </code></pre>
  <p>Thank you in advance,</p>
  <p>Benji</p>
  <p>edit: the model runs fine when I use just the first 100 rows of the dataset. Looks like I just need someway to make it speedier.</p>