Type:	Package
Title:	A GeoJson Processing Toolkit
Version:	1.1.2
Date:	2025-01-13
BugReports:	https://github.com/mlampros/geojsonR/issues
URL:	https://github.com/mlampros/geojsonR
Description:	Includes functions for processing GeoJson objects https://en.wikipedia.org/wiki/GeoJSON relying on 'RFC 7946' https://datatracker.ietf.org/doc/html/rfc7946. The geojson encoding is based on 'json11', a tiny JSON library for 'C++11' https://github.com/dropbox/json11. Furthermore, the source code is exported in R through the 'Rcpp' and 'RcppArmadillo' packages.
License:	MIT + file LICENSE
Encoding:	UTF-8
Copyright:	inst/COPYRIGHTS
SystemRequirements:	libarmadillo: apt-get install -y libarmadillo-dev (deb)
Depends:	R(≥ 3.2.3)
Imports:	Rcpp (≥ 0.12.9), R6
LinkingTo:	Rcpp, RcppArmadillo (≥ 0.7.6)
Suggests:	testthat, covr, knitr, rmarkdown
VignetteBuilder:	knitr
RoxygenNote:	7.3.2
NeedsCompilation:	yes
Packaged:	2025-01-13 18:37:32 UTC; lampros
Author:	Lampros Mouselimis [aut, cre], Dropbox Inc [cph]
Maintainer:	Lampros Mouselimis <mouselimislampros@gmail.com>
Repository:	CRAN
Date/Publication:	2025-01-13 19:10:05 UTC

returns a json-dump from a geojson file

Description

returns a json-dump from a geojson file

Usage

Dump_From_GeoJson(url_file)

Arguments

Value

a character string (json dump)

Examples

## Not run: 

library(geojsonR)

res = Dump_From_GeoJson("/myfolder/point.geojson")

## End(Not run)

reads GeoJson data

Description

reads GeoJson data

Usage

FROM_GeoJson(
  url_file_string,
  Flatten_Coords = FALSE,
  Average_Coordinates = FALSE,
  To_List = FALSE
)

Arguments

Details

The FROM_GeoJson function is based on the 'RFC 7946' specification. Thus, geojson files/strings which include property-names other than the 'RFC 7946' specifies will return an error. To avoid errors of that kind a user should take advantage of the FROM_GeoJson_Schema function, which is not as strict concerning the property names.

Value

a (nested) list

Examples

## Not run: 

library(geojsonR)


# INPUT IS A FILE

res = FROM_GeoJson(url_file_string = "/myfolder/feature_collection.geojson")


# INPUT IS A GEOJSON (character string)

tmp_str = '{ "type": "MultiPolygon", "coordinates": [
  [[[102.0, 2.0], [103.0, 2.0], [103.0, 3.0], [102.0, 3.0], [102.0, 2.0]]],
  [[[100.0, 0.0], [101.0, 0.0], [101.0, 1.0], [100.0, 1.0], [100.0, 0.0]],
   [[100.2, 0.2], [100.8, 0.2], [100.8, 0.8], [100.2, 0.8], [100.2, 0.2]]]
  ]
}'

res = FROM_GeoJson(url_file_string = tmp_str)


# INPUT IS A URL

res = FROM_GeoJson(url_file_string = "http://www.EXAMPLE_web_page.geojson")

## End(Not run)

reads GeoJson data using a one-word-schema

Description

reads GeoJson data using a one-word-schema

Usage

FROM_GeoJson_Schema(
  url_file_string,
  geometry_name = "",
  Average_Coordinates = FALSE,
  To_List = FALSE
)

Arguments

Details

This function is appropriate when the property-names do not match exactly the 'RFC 7946' specification ( for instance if the geometry object-name appears as location as is the case sometimes in mongodb queries ). The user can then specify the geometry_name as it exactly appears in the .geojson string/file (consult the example for more details). If no geometry_name is given then recursion will be used, which increases the processing time. In case that the input .geojson object is of type : Point, LineString, MultiPoint, Polygon, GeometryCollection, MultiLineString, MultiPolygon, Feature or FeatureCollection with a second attribute name : coordinates, then the geometry_name parameter is not necessary.

Value

a (nested) list

Examples

library(geojsonR)


# INPUT IS A GEOJSON (character string)

tmp_str = '{
            "name" : "example_name",
            "location" : {
                "type" : "Point",
                "coordinates" : [ -120.24, 39.21 ]
              }
           }'

res = FROM_GeoJson_Schema(url_file_string = tmp_str, geometry_name = "location")

creates a FeatureCollection dump from multiple Feature geojson objects

Description

creates a FeatureCollection dump from multiple Feature geojson objects

Usage

Features_2Collection(
  Features_files_vec,
  bbox_vec = NULL,
  write_path = NULL,
  verbose = FALSE
)

Arguments

Details

The Features_2Collection function utilizes internally a for-loop. In case of an error set the verbose parameter to TRUE to find out which file leads to this error.

Value

a FeatureCollection dump

Examples

## Not run: 

library(geojsonR)

vec_files = c("/myfolder/Feature1.geojson", "/myfolder/Feature2.geojson",
              "/myfolder/Feature3.geojson", "/myfolder/Feature4.geojson",
              "/myfolder/Feature5.geojson")

res = Features_2Collection(vec_files, bbox_vec = NULL)

## End(Not run)

converts data to a GeoJson object

Description

converts data to a GeoJson object

converts data to a GeoJson object

Usage

# utl <- TO_GeoJson$new()

Value

a List

Methods

TO_GeoJson$new()

--------------

Point(data, stringify = FALSE)

--------------

MultiPoint(data, stringify = FALSE)

--------------

LineString(data, stringify = FALSE)

--------------

MultiLineString(data, stringify = FALSE)

--------------

Polygon(data, stringify = FALSE)

--------------

MultiPolygon(data, stringify = FALSE)

--------------

GeometryCollection(data, stringify = FALSE)

--------------

Feature(data, stringify = FALSE)

--------------

FeatureCollection(data, stringify = FALSE)

--------------

Methods

Public methods

• TO_GeoJson$new()

• TO_GeoJson$Point()

• TO_GeoJson$MultiPoint()

• TO_GeoJson$LineString()

• TO_GeoJson$MultiLineString()

• TO_GeoJson$Polygon()

• TO_GeoJson$MultiPolygon()

• TO_GeoJson$GeometryCollection()

• TO_GeoJson$Feature()

• TO_GeoJson$FeatureCollection()

• TO_GeoJson$clone()

Method new()

Usage

TO_GeoJson$new()

Method Point()

Usage

TO_GeoJson$Point(data, stringify = FALSE)

Arguments

Method MultiPoint()

Usage

TO_GeoJson$MultiPoint(data, stringify = FALSE)

Arguments

Method LineString()

Usage

TO_GeoJson$LineString(data, stringify = FALSE)

Arguments

Method MultiLineString()

Usage

TO_GeoJson$MultiLineString(data, stringify = FALSE)

Arguments

Method Polygon()

Usage

TO_GeoJson$Polygon(data, stringify = FALSE)

Arguments

Method MultiPolygon()

Usage

TO_GeoJson$MultiPolygon(data, stringify = FALSE)

Arguments

Method GeometryCollection()

Usage

TO_GeoJson$GeometryCollection(data, stringify = FALSE)

Arguments

Method Feature()

Usage

TO_GeoJson$Feature(data, stringify = FALSE)

Arguments

Method FeatureCollection()

Usage

TO_GeoJson$FeatureCollection(data, stringify = FALSE)

Arguments

Method clone()

The objects of this class are cloneable with this method.

Usage

TO_GeoJson$clone(deep = FALSE)

Arguments

Examples

library(geojsonR)


# initialize class

init = TO_GeoJson$new()


# Examples covering all geometry-objects


# Point

point_dat = c(100, 1.01)

point = init$Point(point_dat, stringify = TRUE)
point


# MultiPoint

multi_point_dat = list(c(100, 1.01), c(200, 2.01))

multi_point = init$MultiPoint(multi_point_dat, stringify = TRUE)
multi_point


# LineString

linestring_dat = list(c(100, 1.01), c(200, 2.01))

line_string = init$LineString(linestring_dat, stringify = TRUE)
line_string


# MultiLineString

multilinestring_dat = list(list(c(100, 0.0), c(101, 1.0)), list(c(102, 2.0), c(103, 3.0)))

multiline_string = init$MultiLineString(multilinestring_dat, stringify = TRUE)
multiline_string


# Polygon (WITHOUT interior rings)

polygon_WITHOUT_dat = list(list(c(100, 1.01), c(200, 2.01), c(100, 1.0), c(100, 1.01)))

polygon_without = init$Polygon(polygon_WITHOUT_dat, stringify = TRUE)
polygon_without


# Polygon (WITH interior rings)

polygon_WITH_dat = list(list(c(100, 1.01), c(200, 2.01), c(100, 1.0), c(100, 1.01)),

                   list(c(50, 0.5), c(50, 0.8), c(50, 0.9), c(50, 0.5)))

polygon_with = init$Polygon(polygon_WITH_dat, stringify = TRUE)
polygon_with


# MultiPolygon

# the first polygon is without interior rings and the second one is with interior rings

multi_polygon_dat = list(list(list(c(102, 2.0), c(103, 2.0), c(103, 3.0), c(102, 2.0))),

                         list(list(c(100, 0.0), c(101, 1.0), c(101, 1.0), c(100, 0.0)),

                              list(c(100.2, 0.2), c(100.2, 0.8), c(100.8, 0.8), c(100.2, 0.2))))

multi_polygon = init$MultiPolygon(multi_polygon_dat, stringify = TRUE)
multi_polygon



# GeometryCollection (named list)


Point = c(100, 1.01)

MultiPoint = list(c(100, 1.01), c(200, 2.01))

MultiLineString = list(list(c(100, 0.0), c(101, 1.0)),

                  list(c(102, 2.0), c(103, 3.0)))

LineString = list(c(100, 1.01), c(200, 2.01))

MultiLineString = list(list(c(100, 0.0), c(101, 1.0)),

                  list(c(102, 2.0), c(103, 3.0)))

Polygon = list(list(c(100, 1.01), c(200, 2.01), c(100, 1.0), c(100, 1.01)))

Polygon = list(list(c(100, 1.01), c(200, 2.01), c(100, 1.0), c(100, 1.01)),

               list(c(50, 0.5), c(50, 0.8), c(50, 0.9), c(50, 0.5)))

MultiPolygon = list(list(list(c(102, 2.0), c(103, 2.0), c(103, 3.0), c(102, 2.0))),

                    list(list(c(100, 0.0), c(101, 1.0), c(101, 1.0), c(100, 0.0)),

                    list(c(100.2, 0.2), c(100.2, 0.8), c(100.8, 0.8), c(100.2, 0.2))))


geometry_collection_dat = list(Point = Point, MultiPoint = MultiPoint,

                               MultiLineString = MultiLineString, LineString = LineString,

                               MultiLineString = MultiLineString, Polygon = Polygon,

                               Polygon = Polygon, MultiPolygon = MultiPolygon)


geometry_col = init$GeometryCollection(geometry_collection_dat, stringify = TRUE)
geometry_col


# Feature (named list)


# Empty 'properties' list

feature_dat1 = list(id = 1, bbox = c(1,2,3,4), geometry = list(Point = c(100, 1.01)),

                    properties = list())


# Nested 'properties' list

feature_dat2 = list(id = "1", bbox = c(1,2,3,4), geometry = list(Point = c(100, 1.01)),

                    properties = list(prop0 = 'value0',

                                      prop1 = 0.0, vec = c(1,2,3), lst = list(a = 1, d = 2)))


feature_obj = init$Feature(feature_dat2, stringify = TRUE)
feature_obj
cat(feature_obj$json_dump)



# FeatureCollection (named list)


# takes as input the previously created 'feature_dat1', 'feature_dat2'

feature_col_dat = list(bbox = c(-10.01, -10.01, 10.01, 10.01),

                       features = list(Feature = feature_dat1, Feature = feature_dat2))
feature_col_dat


feature_collection_obj = init$FeatureCollection(feature_col_dat, stringify = TRUE)
feature_collection_obj
cat(feature_collection_obj$json_dump)

merge json files (or any kind of text files) from a directory

Description

merge json files (or any kind of text files) from a directory

Usage

merge_files(
  INPUT_FOLDER,
  OUTPUT_FILE,
  CONCAT_DELIMITER = "\n",
  verbose = FALSE
)

Arguments

Details

This function is meant for json files but it can be applied to any kind of text files. It takes an input folder (INPUT_FOLDER) and an output file (OUTPUT_FILE) and merges all files from the INPUT_FOLDER to a single OUTPUT_FILE using the concatenation delimiter (CONCAT_DELIMITER).

Examples

## Not run: 
library(geojsonR)

merge_files(INPUT_FOLDER = "/my_folder/", OUTPUT_FILE = "output_file.json")

## End(Not run)

creates a FeatureCollection from R list objects ( see the details section about the limitations of this function )

Description

creates a FeatureCollection from R list objects ( see the details section about the limitations of this function )

Usage

save_R_list_Features_2_FeatureCollection(
  input_list,
  path_to_file = "",
  verbose = FALSE
)

Arguments

Details

• it allows the following attributes: 'type', 'id', 'properties' and 'geometry'

• it allows only coordinates of type 'Polygon' or 'MultiPolygon' to be processed. In case of a 'Polygon' there are 2 cases: (a.) Polygon WITHOUT interior rings (a numeric matrix is expected) and (b.) Polygon WITH interior rings (a list of numeric matrices is expected). See the test-cases if you receive an error for the correct format of the input data. In case of a 'MultiPolygon' both Polygons with OR without interior rings can be included. Multipolygons are of the form: list of lists where each SUBLIST can be either a numeric matrix (Polygon without interior rings) or a list (Polygon with interior rings)

• the properties attribute must be a list that can take only character strings, numeric and integer values of SIZE 1. In case that any of the input properties is of SIZE > 1 then it will throw an error.

The input_list parameter can be EITHER created from scratch OR GeoJson Features (in form of a FeatureCollection) can be loaded in R and modified so that this list can be processed by this function

Value

a FeatureCollection in form of a character string

a FeatureCollection saved in a file

Examples

## Not run: 

library(geojsonR)

#------------------------------------------------
# valid example that will save the data to a file
#------------------------------------------------

Feature1 = list(type ="Feature",
                id = 1L,
                properties = list(prop1 = 'id', prop2 = 1.0234),
                geometry = list(type = 'Polygon',
                                coordinates = matrix(runif(20), nrow = 10, ncol = 2)))

Feature2 = list(type ="Feature",
                id = 2L,
                properties = list(prop1 = 'non-id', prop2 = 6.0987),
                geometry = list(type = 'MultiPolygon',
                                coordinates = list(matrix(runif(20), nrow = 10, ncol = 2),
                                                  matrix(runif(20), nrow = 10, ncol = 2))))

list_features = list(Feature1, Feature2)

path_feat_col = tempfile(fileext = '.geojson')

res = save_R_list_Features_2_FeatureCollection(input_list = list_features,
                                               path_to_file = path_feat_col,
                                               verbose = TRUE)

#-------------------------------------
# validate that the file can be loaded
#-------------------------------------

res_load = FROM_GeoJson_Schema(url_file_string = path_feat_col)
str(res_load)


#----------------------------------------------------
# INVALID data types such as NA's will throw an ERROR
#----------------------------------------------------


Feature1 = list(type ="Feature",
                id = 1L,
                properties = list(prop1 = NA, prop2 = 1.0234),
                geometry = list(type = 'Polygon',
                                coordinates = matrix(runif(20), nrow = 10, ncol = 2)))

list_features = list(Feature1, Feature2)

path_feat_col = tempfile(fileext = '.geojson')

res = save_R_list_Features_2_FeatureCollection(input_list = list_features,
                                               path_to_file = path_feat_col,
                                               verbose = TRUE)

## End(Not run)

secondary function for shiny Applications

Description

secondary function for shiny Applications

Usage

shiny_from_JSON(input_file)

Arguments

Details

This function is meant for shiny Applications. To read a GeoJson file use either the FROM_GeoJson or FROM_GeoJson_Schema function.

Value

a (nested) list