lawn
lawn
is an R wrapper for the Javascript library turf.js. In addition, we have a few functions to interface with the geojson-random and geojsonhint Javascript libraries, for generating random GeoJSON objects and linting GeoJSON, respectively.
Install
The latest release of lawn
is available from CRAN. To install:
install.packages("lawn")
To install the development version:
install.packages("devtools")
devtools::install_github("ropensci/lawn")
library("lawn")
count
Count number of points within polygons
lawn_count(lawn_data$polygons_count, lawn_data$points_count, 'population')
#> <FeatureCollection>
#> Bounding box: -112.1 46.6 -112.0 46.6
#> No. features: 2
#> No. points: 20
#> Properties:
#> values count
#> 1 200, 600 2
#> 2 0
average
Average value of a field for a set of points within a set of polygons
lawn_average(polygons = lawn_data$polygons_average, points = lawn_data$points_average, 'population')
#> <FeatureCollection>
#> Bounding box: 10.7 59.9 10.9 59.9
#> No. features: 2
#> No. points: 20
#> Properties:
#> values average
#> 1 200, 600, 100 300
#> 2 200, 300 250
distance
Define two points
from <- '{
"type": "Feature",
"properties": {},
"geometry": {
"type": "Point",
"coordinates": [-75.343, 39.984]
}
}'
to <- '{
"type": "Feature",
"properties": {},
"geometry": {
"type": "Point",
"coordinates": [-75.534, 39.123]
}
}'
Calculate distance, default units is kilometers (km
)
lawn_distance(from, to)
#> [1] 97.15958
random set of points
lawn_random(n = 2)
#> <FeatureCollection>
#> Bounding box: -179.0 -64.9 175.4 -1.9
#> No. features: 2
#> No. points: 4
#> Properties: NULL
lawn_random(n = 5)
#> <FeatureCollection>
#> Bounding box: -91.1 3.7 140.0 54.0
#> No. features: 5
#> No. points: 10
#> Properties: NULL
random features with geojson-random
Points
gr_point(2)
#> <FeatureCollection>
#> Bounding box: 26.9 -29.1 82.8 44.9
#> No. features: 2
#> No. points: 4
#> Properties: NULL
Positions
gr_position()
#> [1] 147.16514 -10.64865
Polygons
gr_polygon(n = 1, vertices = 5, max_radial_length = 5)
#> <FeatureCollection>
#> Bounding box: -59.5 51.8 -52.7 54.3
#> No. features: 1
#> No. points: 12
#> Properties: NULL
sample from a FeatureCollection
dat <- lawn_data$points_average
lawn_sample(dat, 1)
#> <FeatureCollection>
#> Bounding box: 10.7 59.9 10.7 59.9
#> No. features: 1
#> No. points: 2
#> Properties:
#> population
#> 1 200
lawn_sample(dat, 2)
#> <FeatureCollection>
#> Bounding box: 10.7 59.9 10.8 59.9
#> No. features: 2
#> No. points: 4
#> Properties:
#> population
#> 1 600
#> 2 300
lawn_sample(dat, 3)
#> <FeatureCollection>
#> Bounding box: 10.7 59.9 10.8 59.9
#> No. features: 3
#> No. points: 6
#> Properties:
#> population
#> 1 300
#> 2 600
#> 3 200
extent
lawn_extent(lawn_data$points_average)
#> [1] 10.71579 59.90478 10.80643 59.93162
within
lawn_within(lawn_data$points_within, lawn_data$polygons_within)
#> <FeatureCollection>
#> Bounding box: -46.6 -23.6 -46.6 -23.6
#> No. features: 2
#> No. points: 4
#> Properties: NULL
buffer
dat <- '{
"type": "Feature",
"properties": {},
"geometry": {
"type": "Polygon",
"coordinates": [[
[-112.072391,46.586591],
[-112.072391,46.61761],
[-112.028102,46.61761],
[-112.028102,46.586591],
[-112.072391,46.586591]
]]
}
}'
lawn_buffer(dat, 1, "miles")
#> <Feature>
#> Type: Polygon
#> Bounding box: -112.1 46.6 -112.0 46.6
#> No. points: 74
#> Properties: NULL
view
lawn
includes a tiny helper function for visualizing geojson.
view(lawn_data$points_average)
Or during process of manipulating geojson, view at mostly any time.
Here, we sample at random two points from the same dataset just viewed.
lawn_sample(lawn_data$points_average, 2) %>% view()
Contributors
Meta
- Please report any issues or bugs.
- License: MIT
- Get citation information for
lawn
in R doingcitation(package = 'lawn')
- Please note that this project is released with a Contributor Code of Conduct. By participating in this project you agree to abide by its terms.
Additional disclaimer
Portions of this code have been contributed by Jeff Hollister, US EPA. As such, that code is subjec to the following disclaimer: https://www.epa.gov/home/github-contribution-disclaimer