@turf/invariant
Advanced tools
@turf/invariant is a module within the Turf.js library that provides utility functions for validating and extracting GeoJSON objects. It ensures that the input data conforms to the expected GeoJSON format, which is crucial for performing various geospatial operations.
getCoord
The `getCoord` function extracts the coordinates from a GeoJSON Point feature. This is useful when you need to work directly with the coordinates of a point.
const turf = require('@turf/invariant');
const point = { type: 'Feature', geometry: { type: 'Point', coordinates: [102.0, 0.5] } };
const coord = turf.getCoord(point);
console.log(coord); // [102.0, 0.5]getCoords
The `getCoords` function extracts the coordinates from a GeoJSON LineString or Polygon feature. This is useful for accessing the array of coordinates that make up the geometry.
const turf = require('@turf/invariant');
const line = { type: 'Feature', geometry: { type: 'LineString', coordinates: [[102.0, 0.0], [103.0, 1.0]] } };
const coords = turf.getCoords(line);
console.log(coords); // [[102.0, 0.0], [103.0, 1.0]]getGeom
The `getGeom` function extracts the geometry object from a GeoJSON feature. This is useful when you need to work with the geometry independently of the feature properties.
const turf = require('@turf/invariant');
const feature = { type: 'Feature', geometry: { type: 'Polygon', coordinates: [[[102.0, 0.0], [103.0, 1.0], [104.0, 0.0], [102.0, 0.0]]] } };
const geom = turf.getGeom(feature);
console.log(geom); // { type: 'Polygon', coordinates: [[[102.0, 0.0], [103.0, 1.0], [104.0, 0.0], [102.0, 0.0]]] }getType
The `getType` function returns the type of a GeoJSON object. This is useful for validating the type of geometry you are working with.
const turf = require('@turf/invariant');
const feature = { type: 'Feature', geometry: { type: 'Polygon', coordinates: [[[102.0, 0.0], [103.0, 1.0], [104.0, 0.0], [102.0, 0.0]]] } };
const type = turf.getType(feature);
console.log(type); // 'Polygon'The `geojson-validation` package provides functions to validate GeoJSON objects against the GeoJSON specification. It is similar to @turf/invariant in that it ensures the input data conforms to the expected GeoJSON format, but it focuses more on validation rather than extraction of specific components.
The `geojson-utils` package offers a set of utility functions for working with GeoJSON data, including validation, distance calculations, and bounding box operations. It provides broader functionality compared to @turf/invariant, which is more focused on validation and extraction.
Unwrap a coordinate from a Point Feature, Geometry or a single coordinate.
Parameters
Examples
var pt = turf.point([10, 10]);
var coord = turf.getCoord(pt);
//= [10, 10]
Returns Array<number> coordinates
Unwrap coordinates from a Feature, Geometry Object or an Array of numbers
Parameters
Examples
var poly = turf.polygon([[[119.32, -8.7], [119.55, -8.69], [119.51, -8.54], [119.32, -8.7]]]);
var coord = turf.getCoords(poly);
//= [[[119.32, -8.7], [119.55, -8.69], [119.51, -8.54], [119.32, -8.7]]]
Returns Array<number> coordinates
Checks if coordinates contains a number
Parameters
coordinates Array<any> GeoJSON CoordinatesReturns boolean true if Array contains a number
Enforce expectations about types of GeoJSON objects for Turf.
Parameters
value GeoJSON any GeoJSON object
type string expected GeoJSON type
name string name of calling function
Throws Error if value is not the expected type.
Enforce expectations about types of Feature inputs for Turf. Internally this uses geojsonType to judge geometry types.
Parameters
feature Feature a feature with an expected geometry type
type string expected GeoJSON type
name string name of calling function
Throws Error error if value is not the expected type.
Enforce expectations about types of FeatureCollection inputs for Turf. Internally this uses geojsonType to judge geometry types.
Parameters
featureCollection FeatureCollection a FeatureCollection for which features will be judged
type string expected GeoJSON type
name string name of calling function
Throws Error if value is not the expected type.
Get Geometry from Feature or Geometry Object
Parameters
Examples
var point = {
"type": "Feature",
"properties": {},
"geometry": {
"type": "Point",
"coordinates": [110, 40]
}
}
var geom = turf.getGeom(point)
//={"type": "Point", "coordinates": [110, 40]}
Returns (Geometry | null) GeoJSON Geometry Object
Get Geometry Type from Feature or Geometry Object
Parameters
Examples
var point = {
"type": "Feature",
"properties": {},
"geometry": {
"type": "Point",
"coordinates": [110, 40]
}
}
var geom = turf.getGeom(point)
//="Point"
Returns string GeoJSON Geometry Type
This module is part of the Turfjs project, an open source module collection dedicated to geographic algorithms. It is maintained in the Turfjs/turf repository, where you can create PRs and issues.
Install this module individually:
$ npm install @turf/invariant
Or install the Turf module that includes it as a function:
$ npm install @turf/turf
4.6.0
@turf/clean-coords Removes redundant coordinates from any GeoJSON Geometry.
(PR https://github.com/Turfjs/turf/pull/875 - Author @stebogit)@turf/interpolate Takes a set of points and estimates their 'property' values on a grid using the Inverse Distance Weighting (IDW) method..
(PR https://github.com/Turfjs/turf/pull/832 - Author @stebogit)@turf/clusters-dbscan Takes a set of Points and partition them into clusters according to DBSCAN's data clustering algorithm.
(PR https://github.com/Turfjs/turf/pull/812 and https://github.com/Turfjs/turf/pull/851 - Author @DenisCarriere)
special mention to this incredibly instructive and fun interactive map by @DenisCarriere 😎👏
@turf/clusters Provides getCluster, clusterEach, and clusterReduce functions.
(PR https://github.com/Turfjs/turf/pull/847 - Author @DenisCarriere)@turf/boolean-point-on-line Returns true if a point is on a line. Accepts a optional parameter to ignore the start and end vertices of the linestring.
(PR https://github.com/Turfjs/turf/pull/858 - Author @rowanwins)@turf/boolean-overlap Takes two features and returns true or false whether or not they overlap, i.e. whether any pair of edges on the two polygons intersect. If there
are any edge intersections, the polygons overlap.
(PR https://github.com/Turfjs/turf/pull/856 and https://github.com/Turfjs/turf/pull/868 - Author @stebogit @tcql)@turf/boolean-equal Determine whether two geometries of the same type have identical X,Y coordinate values.
(PR https://github.com/Turfjs/turf/pull/869 - Author @stebogit @tcql)centered param default to true in @turf/point-grid
(PR https://github.com/Turfjs/turf/pull/836 - Contributor @stebogit)MultiLineString support for @turf/point-on-line
(PR https://github.com/Turfjs/turf/pull/838 - Contributor @stebogit)@turf/clusters => @turf/clusters-kmeans, plus adds deprecated warning message to @turf/clusters@4.5.2
(See Issue https://github.com/Turfjs/turf/issues/845)@turf/clusters-kmeans
(See Issue https://github.com/Turfjs/turf/issues/850 - Contributor @DenisCarriere)segmentEach and segmentReduce functions to @turf/meta
(See Issue https://github.com/Turfjs/turf/issues/850 - Contributor @DenisCarriere)turf-www; see Issue https://github.com/Turfjs/turf/issues/859
(PR https://github.com/Turfjs/turf/issues/857 + https://github.com/Turfjs/turf/issues/864 + https://github.com/Turfjs/turf/issues/870 - Contributor @DenisCarriere @stebogit)null Geometry support across TurfJS modules (See Issue https://github.com/Turfjs/turf/issues/853)
(PR https://github.com/Turfjs/turf/issues/866 - Contributor @DenisCarriere)coordEach/coordReduce (@turf/meta) 🎉
(PR https://github.com/Turfjs/turf/issues/872 - Contributor @DenisCarriere)bbox and id params plus geometry method to @turf/helpers
(PR https://github.com/Turfjs/turf/issues/877 - Contributor @DenisCarriere)@turf/truncate to @turf/line-split
splitter input to avoid approximation errors. Fixed #852
(PR https://github.com/Turfjs/turf/pull/855)@turf-mask error (See Issue https://github.com/Turfjs/turf/issues/837)
(PR https://github.com/Turfjs/turf/pull/865 - Contributor @thiagoxvo)create-new-module script error on LICENSE file creation (See Issue https://github.com/Turfjs/turf/issues/861)
(commit df6986e)@turf/isobands error on commonProperties (See Issue https://github.com/Turfjs/turf/issues/831)
(commit 1663f07)FAQs
turf invariant module
The npm package @turf/invariant receives a total of 176,592 weekly downloads. As such, @turf/invariant popularity was classified as popular.
We found that @turf/invariant demonstrated a healthy version release cadence and project activity because the last version was released less than a year ago. It has 9 open source maintainers collaborating on the project.
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