redist.findparams: Run parameter testing for 'redist.flip'

In redist: Simulation Methods for Legislative Redistricting

Run parameter testing for redist.flip

Description

redist.findparams is used to find optimal parameter values of redist_flip for a given map.

Usage

redist.findparams(
  map,
  nsims,
  init_plan = NULL,
  adapt_lambda = FALSE,
  adapt_eprob = FALSE,
  params,
  ssdmat = NULL,
  group_pop = NULL,
  counties = NULL,
  nstartval_store = 1,
  maxdist_startval = 100,
  maxiterrsg = 5000,
  report_all = TRUE,
  parallel = FALSE,
  ncores = NULL,
  log = FALSE,
  verbose = TRUE
)

Arguments

map	A redist_map object.
nsims	The number of simulations run before a save point.
init_plan	A vector containing the congressional district labels of each geographic unit. The default is NULL. If not provided, random and contiguous congressional district assignments will be generated using redist.rsg.
adapt_lambda	Whether to adaptively tune the lambda parameter so that the Metropolis-Hastings acceptance probability falls between 20% and 40%. Default is FALSE.
adapt_eprob	Whether to adaptively tune the edgecut probability parameter so that the Metropolis-Hastings acceptance probability falls between 20% and 40%. Default is FALSE.
params	A matrix of parameter values to test, such as the output of expand.grid. Parameters accepted for params include eprob, lambda, pop_tol, beta, and constraint.
ssdmat	A matrix of squared distances between geographic units. The default is NULL.
group_pop	A vector of populations for some sub-group of interest. The default is NULL.
counties	A vector of county membership assignments. The default is NULL.
nstartval_store	The number of maps to sample from the preprocessing chain for use as starting values in future simulations. Default is 1.
maxdist_startval	The maximum distance from the starting map that sampled maps should be. Default is 100 (no restriction).
maxiterrsg	Maximum number of iterations for random seed-and-grow algorithm to generate starting values. Default is 5000.
report_all	Whether to report all summary statistics for each set of parameter values. Default is TRUE.
parallel	Whether to run separate parameter settings in parallel. Default is FALSE.
ncores	Number of parallel tasks to run, declared outside of the function. Default is NULL.
log	Whether to open a log to track progress for each parameter combination being tested. Default is FALSE.
verbose	Whether to print additional information about the tests. Default is TRUE.

Details

This function allows users to test multiple parameter settings of redist.flip in preparation for a longer run for analysis.

Value

redist.findparams returns a print-out of summary statistics about each parameter setting.

References

Fifield, Benjamin, Michael Higgins, Kosuke Imai and Alexander Tarr. (2016) "A New Automated Redistricting Simulator Using Markov Chain Monte Carlo." Working Paper. Available at http://imai.princeton.edu/research/files/redist.pdf.

Examples

data(fl25)
data(fl25_enum)
data(fl25_adj)

## Get an initial partition
init_plan <- fl25_enum$plans[, 5118]

params <- expand.grid(eprob = c(.01, .05, .1))

# Make map
map_fl <- redist_map(fl25, ndists = 3, pop_tol = 0.2)
## Run the algorithm
redist.findparams(map_fl,
    init_plan = init_plan, nsims = 10000, params = params)

redist documentation built on April 3, 2023, 5:46 p.m.