import GeographicTransformation from "@arcgis/core/geometry/operators/support/GeographicTransformation.js";const GeographicTransformation = await $arcgis.import("@arcgis/core/geometry/operators/support/GeographicTransformation.js");- Inheritance:
- GeographicTransformation→
Accessor
- Since
- ArcGIS Maps SDK for JavaScript 4.32
Create a geographic transformation that can be used to project 2D geometries between different geographic coordinate systems to ensure that data is properly aligned within a map. These transformations are used to transform coordinates between spatial references that have different geographic coordinate systems, and thus different datums.
A geographic transformation converts everything that needs to be changed, including the units, prime meridian, and the ellipsoid. The transformation is defined by a series of steps, each of which is defined by a well-known text (WKT) string or a well-known ID (WKID). Using the most suitable transformation ensures the best possible accuracy when converting geometries from one spatial reference to another.
The geographicTransformationUtils module provides the getTransformation() and
getTransformations() methods which return the default geographic transformation
for the given projection or a list of suitable geographic transformations.
Known Limitations
Currently, the client-side projectOperator only supports equation-based geographic transformations.
Constructors
Constructor
Parameters
| Parameter | Type | Description | Required |
|---|---|---|---|
| properties | | |
Properties
| Property | Type | Class |
|---|---|---|
declaredClass readonly inherited | ||
| |
steps
- Type
- GeographicTransformationStep[]
An ordered list of geographic transformation steps that represent the process of transforming coordinates from one geographic coordinate system to another. The steps are applied in the order in which they are defined.
To define the steps use the GeographicTransformationStep module.
- Default value
- []
Methods
fromJSON
- Signature
-
fromJSON (json: any): any
Creates a new instance of this class and initializes it with values from a JSON object
generated from an ArcGIS product. The object passed into the input json
parameter often comes from a response to a query operation in the REST API or a
toJSON()
method from another ArcGIS product. See the Using fromJSON()
topic in the Guide for details and examples of when and how to use this function.
Parameters
| Parameter | Type | Description | Required |
|---|---|---|---|
| json | A JSON representation of the instance in the ArcGIS format. See the ArcGIS REST API documentation for examples of the structure of various input JSON objects. | |
- Returns
- any
Returns a new instance of this class.
clone
- Signature
-
clone (): this
Creates a deep clone of this object. Any properties that store values by reference will be assigned copies of the referenced values on the cloned instance.
- Returns
- this
A deep clone of the class instance that invoked this method.
getInverse
- Signature
-
getInverse (): GeographicTransformation
Returns the inverse of this geographic transformation.
The inverse of a transformation converts coordinates using the same method and parameters, but in the opposite
direction of the original object. For example if the original object represents the NAD_1983_HARN_To_NAD_1983_NSRS2007_1
transformation, then the inverse will transform from NAD 83 (NSRS 2007) to NAD 83 (HARN).
- Returns
- GeographicTransformation
toJSON
- Signature
-
toJSON (): any
Converts an instance of this class to its ArcGIS portal JSON representation. See the Using fromJSON() guide topic for more information.
- Returns
- any
The ArcGIS portal JSON representation of an instance of this class.