The Summarize Center and Dispersion task finds central features and directional distributions.
It can be used to answer questions such as:
- Where is the center?
- Which feature is the most accessible from all other features?
- How dispersed, compact, or integrated are the features?
- Are there directional trends?
The point, line, or polygon features to be analyzed.
Syntax: As described in detail in the Feature input topic, this parameter can be one of the following:
The method with which to summarize the analysisLayer.
Values: CentralFeature | MeanCenter | MedianCenter | Ellipse
Example: " summarizeType": "CentralFeature"
The size of the output ellipse in standard deviations. The default ellipse size is 1. Valid choices are 1, 2, or 3 standard deviations.
A numeric field in the analysisLayer to be used to weight locations according to their relative importance.
Example: "weightField": "NumEmployees"
The field used to group features for separate directional distribution calculations. The groupFieldcan be of integer, date, or string type.
Example: "groupField": "Country"
If provided, the task will create a feature service of the results. You define the name of the service. If outputName is not supplied, the task will return a feature collection.
Context contains additional settings that affect task execution. For Summarize Center and Dispersion, there are two settings.
The response format. The default response format is html.
Values: html | json | kmz
When you submit a request, the service assigns a unique job ID for the transaction.
"jobId": "<unique job identifier>",
"jobStatus": "<job status>"
After the initial
request is submitted you can use the
jobId to periodically check the status of the job and messages as described in the topic Checking job status.
Once the job has successfully completed, you use
the jobId to retrieve the results. To track the status, you can make a request of the following form:
When the status of the job request is esriJobSucceded, you can access the results of the analysis by making a request of the following form.
http://<analysis url>/SummarizeCenterAndDispersion/jobs/<jobId>/results/centralFeatureResultLayer?token=<your token>&f=json
The output result.
The result has properties for parameter name, data type, and value. The contents of value depends upon the OutputName parameter provided in the initial request.
See Feature Output for more information about how the result layer or collection is accessed.