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Convert multipart lines or polygons to singlepart

Source: R/explode.R
ms_explode.Rd

For objects of class Spatial (e.g., SpatialPolygonsDataFrame), you may find it faster to use sp::disaggregate.

Usage

ms_explode(input, ...)

Arguments

input

One of:

  • geo_json or character multipart lines, or polygons;

  • multipart SpatialPolygons, SpatialLines;

  • sf or sfc multipart lines, or polygons object

...

Arguments passed on to apply_mapshaper_commands

force_FC

should the output be forced to be a FeatureCollection (or sf object or Spatial*DataFrame) even if there are no attributes? Default TRUE. If FALSE and there are no attributes associated with the geometries, a GeometryCollection (or Spatial object with no dataframe, or sfc) will be output.

sys

Should the system mapshaper be used instead of the bundled mapshaper? Gives better performance on large files. Requires the mapshaper node package to be installed and on the PATH.

sys_mem

How much memory (in GB) should be allocated if using the system mapshaper (sys = TRUE)? Default 8. Ignored if sys = FALSE. This can also be set globally with the option "mapshaper.sys_mem"

quiet

If sys = TRUE, should the mapshaper messages be silenced? Default FALSE. This can also be set globally with the option "mapshaper.sys_quiet"

gj2008

Generate output that is consistent with the pre-RFC 7946 GeoJSON spec (dating to 2008). Polygon rings are CW and holes are CCW, which is the opposite of the default RFC 7946-compatible output. This should be rarely needed, though may be useful when preparing data for D3-based data visualizations (such as plotly::plot_ly()). Default FALSE

Value

same class as input

Details

There is currently no method for SpatialMultiPoints

Examples

library(geojsonsf)
library(sf)

poly <- "{\"type\":\"FeatureCollection\",\"features\":
          [\n{\"type\":\"Feature\",\"geometry\":{\"type\":
          \"MultiPolygon\",\"coordinates\":[[[[102,2],[102,3],
          [103,3],[103,2],[102,2]]],[[[100,0],[100,1],[101,1],
          [101,0],[100,0]]]]},\"properties\":{\"a\":0}}\n]}"

poly <- geojson_sf(poly)
plot(poly)

length(poly)
#> [1] 2
poly
#> Simple feature collection with 1 feature and 1 field
#> Geometry type: MULTIPOLYGON
#> Dimension:     XY
#> Bounding box:  xmin: 100 ymin: 0 xmax: 103 ymax: 3
#> Geodetic CRS:  WGS 84
#>   a                       geometry
#> 1 0 MULTIPOLYGON (((102 2, 102 ...

# Explode the polygon
out <- ms_explode(poly)
plot(out)

length(out)
#> [1] 2
out
#> Simple feature collection with 2 features and 1 field
#> Geometry type: POLYGON
#> Dimension:     XY
#> Bounding box:  xmin: 100 ymin: 0 xmax: 103 ymax: 3
#> Geodetic CRS:  WGS 84
#>   a                       geometry
#> 1 0 POLYGON ((102 2, 103 2, 103...
#> 2 0 POLYGON ((100 0, 101 0, 101...