R/reindex.R

In redist: Simulation Methods for Legislative Redistricting

#' Reorders district numbers
#'
#' Ensures that for each column in the plans object, the first
#' district listed is 1, the second is 2, up to n districts. Assumes that all
#' columns have the same number of districts as the first.
#' @param plans A numeric vector (if only one map) or
#' matrix with one row for each precinct and one column for each map.
#'
#' @return integer matrix
#' @export
#'
#' @examples
#' cds <- matrix(c(rep(c(4L, 5L, 2L, 1L, 3L), 5),
#'     rep(c(5L, 4L, 3L, 2L, 1L), 2), rep(c(4L, 5L, 2L, 1L, 3L), 3)), nrow = 25)
#' redist.reorder(cds)
#'
redist.reorder <- function(plans) {
    # Check inputs
    if (!is.matrix(plans)) {
        if (is.numeric(plans)) {
            plans <- as.matrix(plans, )
        } else {
            cli_abort("{.arg plans} must be a matrix or integer vector.")
        }
    }

    # Prep objects for Rcpp
    nd <- length(unique(plans[, 1]))

    reindex(dm = plans, nd = nd)
}


#' Sink Plans to 1:ndists
#'
#' Takes a plan and renumbers it to be from 1:ndists
#'
#' @param plan vector of assignments, required.
#'
#' @return A vector with an ID that corresponds from 1:ndists
#'
#' @concept prepare
#' @export
#' @examples
#' data(fl25_enum)
#' plan <- fl25_enum$plans[, 5118]
#' # Subset based on something:
#' plan <- plan[plan != 2]
#' plan <- redist.sink.plan(plan)
#' # Now plan can be used with redist.flip()
#' plan
#'
redist.sink.plan <- function(plan) {
    if (is.character(plan) || is.numeric(plan)) {
        uc <- unique(sort(plan))
        plan_id <- rep(0, length(plan))
        for (i in 1:length(plan)) {
            plan_id[i] <- which(uc == plan[i])
        }
    } else {
        stop('Please provide "plan" as a  numeric or integer vector.')
    }

    plan_id
}