future_simplify: Parallel implementation of 'rmapshaper::ms_simplify'
In h-a-graham/sfurrr: Run spatial joins and filters with {sf} in parallel

View source: R/future_simplify.R

future_simplify

R Documentation

Parallel implementation of `rmapshaper::ms_simplify`

Description

simply splits up an sf and runs the simplify algorithm on each chunk. Uses mapshaper to simplify polygons. Currently only supports sf objects.

Usage

future_simplify(
  x,
  keep = 0.05,
  method = NULL,
  weighting = 0.7,
  keep_shapes = FALSE,
  no_repair = FALSE,
  snap = TRUE,
  explode = FALSE,
  drop_null_geometries = TRUE,
  snap_interval = NULL,
  nchunks = 1,
  .progress = FALSE
)

Arguments

`x`	spatial object to simplify. One of: `sf` or `sfc` polygons or lines object
`keep`	proportion of points to retain (0-1; default 0.05)
`method`	simplification method to use: `"vis"` for Visvalingam algorithm, or `"dp"` for Douglas-Peuker algorithm. If left as `NULL` (default), uses Visvalingam simplification but modifies the area metric by underweighting the effective area of points at the vertex of more acute angles, resulting in a smoother appearance. See this https://github.com/mbloch/mapshaper/wiki/Simplification-Tipslink for more information.
`weighting`	Coefficient for weighting Visvalingam simplification (default is 0.7). Higher values produce smoother output. weighting=0 is equivalent to unweighted Visvalingam simplification.
`keep_shapes`	Prevent small polygon features from disappearing at high simplification (default `FALSE`)
`no_repair`	disable intersection repair after simplification (default `FALSE`).
`snap`	Snap together vertices within a small distance threshold to fix small coordinate misalignment in adjacent polygons. Default `TRUE`.
`explode`	Should multipart polygons be converted to singlepart polygons? This prevents small shapes from disappearing during simplification if `keep_shapes = TRUE`. Default `FALSE`
`drop_null_geometries`	should Features with null geometries be dropped? Ignored for `Spatial*` objects, as it is always `TRUE`.
`snap_interval`	Specify snapping distance in source units, must be a numeric. Default `NULL`
`nchunks`	The number of chunks to run on each core. Default is 1. Can improve or worsen performance depending on dataset size and number of cores
`.progress`	Show progress bar. Only useful when nchunks > 1. default is FALSE