Remove some points from the point cloud. This stage modifies the point cloud in the pipeline but does not produce any output.
Arguments
- filter
the 'filter' argument allows filtering of the point-cloud to work with points of interest. For a given stage when a filter is applied, only the points that meet the criteria are processed. The most common strings are
Classification == 2","Z > 2","Intensity < 100". For more details see filters.
Examples
f <- system.file("extdata", "Megaplot.las", package="lasR")
read <- reader()
filter <- delete_points(keep_z_above(4))
pipeline <- read + summarise() + filter + summarise()
exec(pipeline, on = f)
#> $summary
#> $summary$npoints
#> [1] 81590
#>
#> $summary$nsingle
#> [1] 34337
#>
#> $summary$nwithheld
#> [1] 0
#>
#> $summary$nsynthetic
#> [1] 0
#>
#> $summary$npoints_per_return
#> 1 2 3 4
#> 55756 21493 3999 342
#>
#> $summary$npoints_per_class
#> 1 2
#> 74201 7389
#>
#> $summary$z_histogram
#> 0 2 4 6 8 10 12 14 16 18 20 22 24
#> 11031 1256 2476 3994 4295 4898 5943 7115 8557 9934 10353 7520 3156
#> 26 28 30
#> 955 103 4
#>
#> $summary$i_histogram
#> 0 50 100 150 200 250 300 350 400 450 500 550 600
#> 43359 37956 204 42 16 6 2 0 1 1 2 0 1
#>
#> $summary$crs
#> [1] "PROJCRS[\"NAD83 / UTM zone 17N\",BASEGEOGCRS[\"NAD83\",DATUM[\"North American Datum 1983\",ELLIPSOID[\"GRS 1980\",6378137,298.257222101,LENGTHUNIT[\"metre\",1]]],PRIMEM[\"Greenwich\",0,ANGLEUNIT[\"degree\",0.0174532925199433]],ID[\"EPSG\",4269]],CONVERSION[\"UTM zone 17N\",METHOD[\"Transverse Mercator\",ID[\"EPSG\",9807]],PARAMETER[\"Latitude of natural origin\",0,ANGLEUNIT[\"degree\",0.0174532925199433],ID[\"EPSG\",8801]],PARAMETER[\"Longitude of natural origin\",-81,ANGLEUNIT[\"degree\",0.0174532925199433],ID[\"EPSG\",8802]],PARAMETER[\"Scale factor at natural origin\",0.9996,SCALEUNIT[\"unity\",1],ID[\"EPSG\",8805]],PARAMETER[\"False easting\",500000,LENGTHUNIT[\"metre\",1],ID[\"EPSG\",8806]],PARAMETER[\"False northing\",0,LENGTHUNIT[\"metre\",1],ID[\"EPSG\",8807]]],CS[Cartesian,2],AXIS[\"(E)\",east,ORDER[1],LENGTHUNIT[\"metre\",1]],AXIS[\"(N)\",north,ORDER[2],LENGTHUNIT[\"metre\",1]],USAGE[SCOPE[\"Engineering survey, topographic mapping.\"],AREA[\"North America - between 84°W and 78°W - onshore and offshore. Canada - Nunavut; Ontario; Quebec. United States (USA) - Florida; Georgia; Kentucky; Maryland; Michigan; New York; North Carolina; Ohio; Pennsylvania; South Carolina; Tennessee; Virginia; West Virginia.\"],BBOX[23.81,-84,84,-78]],ID[\"EPSG\",26917]]"
#>
#> $summary$epsg
#> [1] 26917
#>
#>
#> $summary.1
#> $summary.1$npoints
#> [1] 68328
#>
#> $summary.1$nsingle
#> [1] 26693
#>
#> $summary.1$nwithheld
#> [1] 0
#>
#> $summary.1$nsynthetic
#> [1] 0
#>
#> $summary.1$npoints_per_return
#> 1 2 3 4
#> 47919 18297 2058 54
#>
#> $summary.1$npoints_per_class
#> 1
#> 68328
#>
#> $summary.1$z_histogram
#> 4 6 8 10 12 14 16 18 20 22 24 26 28
#> 1501 3994 4295 4898 5943 7115 8557 9934 10353 7520 3156 955 103
#> 30
#> 4
#>
#> $summary.1$i_histogram
#> 0 50
#> 34738 33590
#>
#> $summary.1$crs
#> [1] "PROJCRS[\"NAD83 / UTM zone 17N\",BASEGEOGCRS[\"NAD83\",DATUM[\"North American Datum 1983\",ELLIPSOID[\"GRS 1980\",6378137,298.257222101,LENGTHUNIT[\"metre\",1]]],PRIMEM[\"Greenwich\",0,ANGLEUNIT[\"degree\",0.0174532925199433]],ID[\"EPSG\",4269]],CONVERSION[\"UTM zone 17N\",METHOD[\"Transverse Mercator\",ID[\"EPSG\",9807]],PARAMETER[\"Latitude of natural origin\",0,ANGLEUNIT[\"degree\",0.0174532925199433],ID[\"EPSG\",8801]],PARAMETER[\"Longitude of natural origin\",-81,ANGLEUNIT[\"degree\",0.0174532925199433],ID[\"EPSG\",8802]],PARAMETER[\"Scale factor at natural origin\",0.9996,SCALEUNIT[\"unity\",1],ID[\"EPSG\",8805]],PARAMETER[\"False easting\",500000,LENGTHUNIT[\"metre\",1],ID[\"EPSG\",8806]],PARAMETER[\"False northing\",0,LENGTHUNIT[\"metre\",1],ID[\"EPSG\",8807]]],CS[Cartesian,2],AXIS[\"(E)\",east,ORDER[1],LENGTHUNIT[\"metre\",1]],AXIS[\"(N)\",north,ORDER[2],LENGTHUNIT[\"metre\",1]],USAGE[SCOPE[\"Engineering survey, topographic mapping.\"],AREA[\"North America - between 84°W and 78°W - onshore and offshore. Canada - Nunavut; Ontario; Quebec. United States (USA) - Florida; Georgia; Kentucky; Maryland; Michigan; New York; North Carolina; Ohio; Pennsylvania; South Carolina; Tennessee; Virginia; West Virginia.\"],BBOX[23.81,-84,84,-78]],ID[\"EPSG\",26917]]"
#>
#> $summary.1$epsg
#> [1] 26917
#>
#>