In performing a county-level or cores-based analysis it is often necessary to merge several units together into a larger unit. This function performs this operation, modifying the adjacency graph as needed and attempting to properly aggregate other data columns.
merge_by(.data, ..., by_existing = TRUE, drop_geom = TRUE, collapse_chr = TRUE)a redist_map object
<tidy-select> the column(s) to merge by
if an existing assignment is present, whether to also group by it
whether to drop the geometry column. Recommended, as otherwise a costly geometric merge is required.
if TRUE, preserve character columns by collapsing
their values. For example, a county name column in Iowa might be merged and
have entries such as "Cedar~Clinton~Des Moines". Set to FALSE to
drop character columns instead.
A merged redist_map object