linestring_split

The splitting function comes from this gist

Data 

geojson <- '{
  "type": "FeatureCollection",
  "name": "sample",
  "features": [
    { "type": "Feature", "properties": { "COMID": 5329303 }, "geometry": { "type": "LineString", "coordinates": [ [ -122.916097119649635, 38.229575873993497 ], [ -122.916154986316201, 38.229346873993904 ], [ -122.916676986315338, 38.228614207328235 ], [ -122.917430786314128, 38.227148873997294 ], [ -122.917488319647418, 38.226210273998674 ], [ -122.917371986314322, 38.22579827399926 ], [ -122.917400319647584, 38.224516407334704 ], [ -122.918995719645125, 38.223348274003115 ], [ -122.920127119643382, 38.223004607336975 ], [ -122.921171719641791, 38.222546407337802 ], [ -122.922186919640126, 38.221950807338601 ], [ -122.922795786305926, 38.221286674006421 ] ] } },
    { "type": "Feature", "properties": { "COMID": 5329293 }, "geometry": { "type": "LineString", "coordinates": [ [ -122.913574186320261, 38.233262207321104 ], [ -122.914618986318601, 38.233261873987772 ], [ -122.915228386317608, 38.23307847398803 ], [ -122.915547519650431, 38.23282660732184 ], [ -122.915866386316679, 38.232231273989385 ], [ -122.915778986316809, 38.231475873990462 ], [ -122.915430386317382, 38.230880807324809 ], [ -122.915400986317422, 38.23044600732544 ], [ -122.91548798631726, 38.23024000732579 ], [ -122.916097119649635, 38.229575873993497 ] ] } },
    { "type": "Feature", "properties": { "COMID": 5329305 }, "geometry": { "type": "LineString", "coordinates": [ [ -122.895114186348906, 38.228161607328957 ], [ -122.895375386348462, 38.22809287399582 ], [ -122.895636519681375, 38.227864007329401 ], [ -122.895897586347701, 38.227337407330253 ], [ -122.89607138634733, 38.226559073998033 ], [ -122.896245519680463, 38.226330073998497 ], [ -122.896071186347342, 38.225597607333043 ], [ -122.896186986347232, 38.224750474000984 ], [ -122.896070786347309, 38.224407207334878 ], [ -122.896041519680807, 38.223354207336399 ], [ -122.895867319681031, 38.223079474003612 ], [ -122.895867186347687, 38.222598874004348 ], [ -122.896070186347345, 38.222324207338033 ], [ -122.896940719679321, 38.221843274005437 ], [ -122.897492119678532, 38.221934674005354 ], [ -122.897985519677775, 38.222323807338 ], [ -122.898565986343442, 38.222529674004477 ], [ -122.89937871967561, 38.223056074003637 ], [ -122.900336386340712, 38.2235366073362 ], [ -122.90106218633963, 38.224406274001467 ], [ -122.901323386339243, 38.224566474001222 ], [ -122.901903719671566, 38.224497674001384 ], [ -122.902164786337892, 38.22429160733509 ], [ -122.902193586337887, 38.223673607336025 ], [ -122.902048519671439, 38.223444674003076 ], [ -122.901438919672387, 38.222941207337044 ], [ -122.901380786339189, 38.222597807337593 ], [ -122.901119519672761, 38.222300207338037 ], [ -122.901119386339587, 38.221819607338773 ], [ -122.901873386338366, 38.220743607340466 ], [ -122.902279586337784, 38.220651874007388 ], [ -122.902714986337116, 38.220651807340687 ], [ -122.902976186336616, 38.220766207340432 ], [ -122.903237519669631, 38.221338474006302 ], [ -122.903556919669086, 38.221704607339007 ], [ -122.904195386334777, 38.222139407338375 ], [ -122.905704586332433, 38.222574007337755 ], [ -122.906662319664292, 38.222940007337115 ], [ -122.908577919661298, 38.223878074002357 ], [ -122.910203519658751, 38.224564407334583 ], [ -122.910580919658173, 38.224999207333951 ], [ -122.910552119658121, 38.225457073999792 ], [ -122.910378119658446, 38.225754673999347 ], [ -122.909623786326392, 38.22628140733184 ], [ -122.908927586327422, 38.227037007330807 ], [ -122.908289519661764, 38.22751787399659 ], [ -122.907767519662571, 38.228456607328496 ], [ -122.90782578632917, 38.22902900732754 ], [ -122.908087186328771, 38.229463673993621 ], [ -122.908377519661599, 38.229738273993235 ], [ -122.909451386326623, 38.230012873992848 ], [ -122.9101481196588, 38.230333073992369 ], [ -122.910409386325057, 38.230653473991879 ], [ -122.910438519658385, 38.230836607324875 ], [ -122.910903119657689, 38.231271473990773 ], [ -122.911367519657006, 38.231591807323582 ], [ -122.911454786323532, 38.231958007323158 ], [ -122.911832319656298, 38.23234707398916 ], [ -122.912557986321815, 38.232667273988682 ], [ -122.913574186320261, 38.233262207321104 ] ] } }
    ]
}'


lines <- suppressMessages( 
  sf::st_transform(sf::st_read(geojson), 5070)
)
#> Reading layer `sample' from data source 
#>   `{
#>   "type": "FeatureCollection",
#>   "name": "sample",
#>   "features": [
#>     { "type": "Feature", "properties": { "COMID": 5329303 }, "geometry": { "type": "LineString", "coordinates": [ [ -122.916097119649635, 38.229575873993497 ], [ -122.916154986316201, 38.229346873993904 ], [ -122.916676986315338, 38.228614207328235 ], [ -122.917430786314128, 38.227148873997294 ], [ -122.917488319647418, 38.226210273998674 ], [ -122.917371986314322, 38.22579827399926 ], [ -122.917400319647584, 38.224516407334704 ], [ -122.918995719645125, 38.223348274003115 ], [ -122.920127119643382, 38.223004607336975 ], [ -122.921171719641791, 38.222546407337802 ], [ -122.922186919640126, 38.221950807338601 ], [ -122.922795786305926, 38.221286674006421 ] ] } },
#>     { "type": "Feature", "properties": { "COMID": 5329293 }, "geometry": { "type": "LineString", "coordinates": [ [ -122.913574186320261, 38.233262207321104 ], [ -122.914618986318601, 38.233261873987772 ], [ -122.915228386317608, 38.23307847398803 ], [ -122.915547519650431, 38.23282660732184 ], [ -122.915866386316679, 38.232231273989385 ], [ -122.915778986316809, 38.231475873990462 ], [ -122.915430386317382, 38.230880807324809 ], [ -122.915400986317422, 38.23044600732544 ], [ -122.91548798631726, 38.23024000732579 ], [ -122.916097119649635, 38.229575873993497 ] ] } },
#>     { "type": "Feature", "properties": { "COMID": 5329305 }, "geometry": { "type": "LineString", "coordinates": [ [ -122.895114186348906, 38.228161607328957 ], [ -122.895375386348462, 38.22809287399582 ], [ -122.895636519681375, 38.227864007329401 ], [ -122.895897586347701, 38.227337407330253 ], [ -122.89607138634733, 38.226559073998033 ], [ -122.896245519680463, 38.226330073998497 ], [ -122.896071186347342, 38.225597607333043 ], [ -122.896186986347232, 38.224750474000984 ], [ -122.896070786347309, 38.224407207334878 ], [ -122.896041519680807, 38.223354207336399 ], [ -122.895867319681031, 38.223079474003612 ], [ -122.895867186347687, 38.222598874004348 ], [ -122.896070186347345, 38.222324207338033 ], [ -122.896940719679321, 38.221843274005437 ], [ -122.897492119678532, 38.221934674005354 ], [ -122.897985519677775, 38.222323807338 ], [ -122.898565986343442, 38.222529674004477 ], [ -122.89937871967561, 38.223056074003637 ], [ -122.900336386340712, 38.2235366073362 ], [ -122.90106218633963, 38.224406274001467 ], [ -122.901323386339243, 38.224566474001222 ], [ -122.901903719671566, 38.224497674001384 ], [ -122.902164786337892, 38.22429160733509 ], [ -122.902193586337887, 38.223673607336025 ], [ -122.902048519671439, 38.223444674003076 ], [ -122.901438919672387, 38.222941207337044 ], [ -122.901380786339189, 38.222597807337593 ], [ -122.901119519672761, 38.222300207338037 ], [ -122.901119386339587, 38.221819607338773 ], [ -122.901873386338366, 38.220743607340466 ], [ -122.902279586337784, 38.220651874007388 ], [ -122.902714986337116, 38.220651807340687 ], [ -122.902976186336616, 38.220766207340432 ], [ -122.903237519669631, 38.221338474006302 ], [ -122.903556919669086, 38.221704607339007 ], [ -122.904195386334777, 38.222139407338375 ], [ -122.905704586332433, 38.222574007337755 ], [ -122.906662319664292, 38.222940007337115 ], [ -122.908577919661298, 38.223878074002357 ], [ -122.910203519658751, 38.224564407334583 ], [ -122.910580919658173, 38.224999207333951 ], [ -122.910552119658121, 38.225457073999792 ], [ -122.910378119658446, 38.225754673999347 ], [ -122.909623786326392, 38.22628140733184 ], [ -122.908927586327422, 38.227037007330807 ], [ -122.908289519661764, 38.22751787399659 ], [ -122.907767519662571, 38.228456607328496 ], [ -122.90782578632917, 38.22902900732754 ], [ -122.908087186328771, 38.229463673993621 ], [ -122.908377519661599, 38.229738273993235 ], [ -122.909451386326623, 38.230012873992848 ], [ -122.9101481196588, 38.230333073992369 ], [ -122.910409386325057, 38.230653473991879 ], [ -122.910438519658385, 38.230836607324875 ], [ -122.910903119657689, 38.231271473990773 ], [ -122.911367519657006, 38.231591807323582 ], [ -122.911454786323532, 38.231958007323158 ], [ -122.911832319656298, 38.23234707398916 ], [ -122.912557986321815, 38.232667273988682 ], [ -122.913574186320261, 38.233262207321104 ] ] } }
#>     ]
#> }' 
#>   using driver `GeoJSON'
#> Simple feature collection with 3 features and 1 field
#> Geometry type: LINESTRING
#> Dimension:     XY
#> Bounding box:  xmin: -122.9228 ymin: 38.22065 xmax: -122.8951 ymax: 38.23326
#> Geodetic CRS:  WGS 84

Split lines 

#This works for sf lines with multiple lines and returns another sf objet
lines_split <- split_lines(lines,id = 'COMID' ,max_length = 10)
mapview( lines_split ,zcol='split_fID')

Remove all end points

Remove a fixed distance in meters 

 


lines_no_endpoints_10 <- remove_line_endpoints(lines,min_distance_m_to_remove = 10,id_col='COMID')
lines_no_endpoints_50 <- remove_line_endpoints(lines,min_distance_m_to_remove = 50,id_col='COMID')
 

 
mapview( lines %>% select(geometry) %>% mutate(type='initial'),color='red') + 
  mapview(lines_no_endpoints_50 %>% select(geometry) %>% mutate(type='endpoints_removed - 50 m'),color='green') +
  mapview(lines_no_endpoints_10 %>% select(geometry) %>% mutate(type='endpoints_removed - 10 m'))

Remove a fixed proportion 

 
lines <- sf::st_transform(sf::st_read(geojson), 5070)
#> Reading layer `sample' from data source 
#>   `{
#>   "type": "FeatureCollection",
#>   "name": "sample",
#>   "features": [
#>     { "type": "Feature", "properties": { "COMID": 5329303 }, "geometry": { "type": "LineString", "coordinates": [ [ -122.916097119649635, 38.229575873993497 ], [ -122.916154986316201, 38.229346873993904 ], [ -122.916676986315338, 38.228614207328235 ], [ -122.917430786314128, 38.227148873997294 ], [ -122.917488319647418, 38.226210273998674 ], [ -122.917371986314322, 38.22579827399926 ], [ -122.917400319647584, 38.224516407334704 ], [ -122.918995719645125, 38.223348274003115 ], [ -122.920127119643382, 38.223004607336975 ], [ -122.921171719641791, 38.222546407337802 ], [ -122.922186919640126, 38.221950807338601 ], [ -122.922795786305926, 38.221286674006421 ] ] } },
#>     { "type": "Feature", "properties": { "COMID": 5329293 }, "geometry": { "type": "LineString", "coordinates": [ [ -122.913574186320261, 38.233262207321104 ], [ -122.914618986318601, 38.233261873987772 ], [ -122.915228386317608, 38.23307847398803 ], [ -122.915547519650431, 38.23282660732184 ], [ -122.915866386316679, 38.232231273989385 ], [ -122.915778986316809, 38.231475873990462 ], [ -122.915430386317382, 38.230880807324809 ], [ -122.915400986317422, 38.23044600732544 ], [ -122.91548798631726, 38.23024000732579 ], [ -122.916097119649635, 38.229575873993497 ] ] } },
#>     { "type": "Feature", "properties": { "COMID": 5329305 }, "geometry": { "type": "LineString", "coordinates": [ [ -122.895114186348906, 38.228161607328957 ], [ -122.895375386348462, 38.22809287399582 ], [ -122.895636519681375, 38.227864007329401 ], [ -122.895897586347701, 38.227337407330253 ], [ -122.89607138634733, 38.226559073998033 ], [ -122.896245519680463, 38.226330073998497 ], [ -122.896071186347342, 38.225597607333043 ], [ -122.896186986347232, 38.224750474000984 ], [ -122.896070786347309, 38.224407207334878 ], [ -122.896041519680807, 38.223354207336399 ], [ -122.895867319681031, 38.223079474003612 ], [ -122.895867186347687, 38.222598874004348 ], [ -122.896070186347345, 38.222324207338033 ], [ -122.896940719679321, 38.221843274005437 ], [ -122.897492119678532, 38.221934674005354 ], [ -122.897985519677775, 38.222323807338 ], [ -122.898565986343442, 38.222529674004477 ], [ -122.89937871967561, 38.223056074003637 ], [ -122.900336386340712, 38.2235366073362 ], [ -122.90106218633963, 38.224406274001467 ], [ -122.901323386339243, 38.224566474001222 ], [ -122.901903719671566, 38.224497674001384 ], [ -122.902164786337892, 38.22429160733509 ], [ -122.902193586337887, 38.223673607336025 ], [ -122.902048519671439, 38.223444674003076 ], [ -122.901438919672387, 38.222941207337044 ], [ -122.901380786339189, 38.222597807337593 ], [ -122.901119519672761, 38.222300207338037 ], [ -122.901119386339587, 38.221819607338773 ], [ -122.901873386338366, 38.220743607340466 ], [ -122.902279586337784, 38.220651874007388 ], [ -122.902714986337116, 38.220651807340687 ], [ -122.902976186336616, 38.220766207340432 ], [ -122.903237519669631, 38.221338474006302 ], [ -122.903556919669086, 38.221704607339007 ], [ -122.904195386334777, 38.222139407338375 ], [ -122.905704586332433, 38.222574007337755 ], [ -122.906662319664292, 38.222940007337115 ], [ -122.908577919661298, 38.223878074002357 ], [ -122.910203519658751, 38.224564407334583 ], [ -122.910580919658173, 38.224999207333951 ], [ -122.910552119658121, 38.225457073999792 ], [ -122.910378119658446, 38.225754673999347 ], [ -122.909623786326392, 38.22628140733184 ], [ -122.908927586327422, 38.227037007330807 ], [ -122.908289519661764, 38.22751787399659 ], [ -122.907767519662571, 38.228456607328496 ], [ -122.90782578632917, 38.22902900732754 ], [ -122.908087186328771, 38.229463673993621 ], [ -122.908377519661599, 38.229738273993235 ], [ -122.909451386326623, 38.230012873992848 ], [ -122.9101481196588, 38.230333073992369 ], [ -122.910409386325057, 38.230653473991879 ], [ -122.910438519658385, 38.230836607324875 ], [ -122.910903119657689, 38.231271473990773 ], [ -122.911367519657006, 38.231591807323582 ], [ -122.911454786323532, 38.231958007323158 ], [ -122.911832319656298, 38.23234707398916 ], [ -122.912557986321815, 38.232667273988682 ], [ -122.913574186320261, 38.233262207321104 ] ] } }
#>     ]
#> }' 
#>   using driver `GeoJSON'
#> Simple feature collection with 3 features and 1 field
#> Geometry type: LINESTRING
#> Dimension:     XY
#> Bounding box:  xmin: -122.9228 ymin: 38.22065 xmax: -122.8951 ymax: 38.23326
#> Geodetic CRS:  WGS 84

lines_no_endpoints_10 <- remove_line_endpoints(lines,min_proportion_remove = 0.1,id_col='COMID')

tryCatch({
  lines_no_endpoints_50 <- remove_line_endpoints(lines,min_proportion_remove = 0.5,id_col='COMID')
},error=function(e){
  print(paste0('Fatal error as expected ', e))
})
#> [1] "Fatal error with 5329303 - Error in remove_line_endpoints_lwgeom(shp_lines[x, ], id_col, min_distance_m_to_remove, : Cannot remove such a large segment! Would remove (for both sides): 100 % of the segment\n"
#> [1] "Fatal error with 5329293 - Error in remove_line_endpoints_lwgeom(shp_lines[x, ], id_col, min_distance_m_to_remove, : Cannot remove such a large segment! Would remove (for both sides): 100 % of the segment\n"
#> [1] "Fatal error with 5329305 - Error in remove_line_endpoints_lwgeom(shp_lines[x, ], id_col, min_distance_m_to_remove, : Cannot remove such a large segment! Would remove (for both sides): 100 % of the segment\n"
#> [1] "Fatal error as expected Error in UseMethod(\"st_transform\"): no applicable method for 'st_transform' applied to an object of class \"NULL\"\n"


lines_no_endpoints_50 <- remove_line_endpoints(lines,min_proportion_remove = 0.49,id_col='COMID')
 
mapview( lines %>% select(geometry) %>% mutate(type='initial'),color='red') + 
  mapview(lines_no_endpoints_50 %>% select(geometry) %>% mutate(type='endpoints_removed - 49%'),color='green') +
  mapview(lines_no_endpoints_10 %>% select(geometry) %>% mutate(type='endpoints_removed - 10%'))