redist_constr objects are used to specify constraints when sampling redistricting plans with redist_smc() and redist_mergesplit(). Each constraint is specified as a function which scores a given plan. Higher scores are penalized and sampled less frequently.

redist_constr(map = tibble())



a redist_map() object; the map that will be used in sampling


a redist_constr object, which is just a list with a certain nested structure.


The redist_constr object keeps track of sampling constraints in a nested list. You can view the exact structure of this list by calling str(). Constraints may be added by using one of the following functions:

More information about each constraint can be found on the relevant constraint page.


map_ia <- redist_map(iowa, existing_plan = cd_2010, pop_tol = 0.01)
constr <- redist_constr(map_ia)
constr <- add_constr_splits(constr, strength = 1.5, admin = region)
#> A <redist_constr> with 1 constraint
#>  A splits constraint of strength 1.5