Takes a column of a `redist_plans` object and averages it across a set of `draws` for each precinct.
avg_by_prec(plans, x, draws = NA)
a `redist_plans` object
an expression to average. Tidy-evaluated in `plans`.
which draws to average. `NULL` will average all draws, including reference plans. The special value `NA` will average all sampled draws. An integer, logical, or character vector indicating specific draws may also be provided.
a vector of length matching the number of precincts, containing the average.