- URL:https://<geoanalytics-url>/SummarizeCenterAndDispersion
- Version Introduced:10.9
Description
The SummarizeCenterAndDispersion task finds central features and directional distributions. It can be used to answer questions such as the following:
- 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?
For an example, suppose you have used the GeoAnalytics tool Find Point Clusters to identify groups of power outages across an entire year. The result will be time-enabled points representing cluster locations of power outages. However, you are interested in identifying the center of the power outages for visualization. To do this, use the tool Summarize Center And Dispersion with the cluster IDs as a group by field.
Note:
If the input layer has a geometry type of line or polygon, the centroids of each feature will be used in analysis.Request parameters
Parameter | Details |
---|---|
inputLayer (Required) | The point, line, or polygon features to be analyzed. Syntax: As described in Feature input, this parameter can be one of the following:
REST examples
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summaryType (Required) | One or more methods with which to summarize the inputLayer. Values: CentralFeature|MeanCenter|MedianCenter|Ellipse REST examples
|
ellipseSize (Optional) | The number of standard deviations represented in the output ellipse layer. The default ellipse size is 1. Valid choices are 1, 2, or 3 standard deviations. This option is only used if Ellipse is chosen from the summaryType parameter. REST examples
|
weightField (Optional) | A numeric field in the inputLayer to be used to weight locations according to their relative importance. REST examples
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groupFields (Optional) | One or more fields used to group features for summarization. The groupFields can be of integer, date, or string type. REST examples
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outputName (Required) | The task will create a feature service of the results. You define the name of the service. REST examples
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context (Optional) | The context parameter contains additional settings that affect task execution. For this task, there are four settings:
|
f | The response format. The default response format is html. Values: html | json |
Example usage
Below is a sample request URL for SummarizeCenterAndDispersion:
https://webadaptor.domain.com/server/rest/services/System/GeoAnalyticsTools/GPServer/SummarizeCenterAndDispersion/submitJob?inputLayer={"url": "https://myportal.domain.com/server/rest/services/Hosted/hurricaneTrack/FeatureServer/0"}&summaryType=Ellipse&ellipseSize=2&outputName=myOutput&f=json
Response
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 jobId to periodically check the status of the job and messages as described in Check job status. Once the job has successfully completed, use jobId to retrieve the results. To track the status, you can make a request of the following form:
https://<analysis url>/SummarizeCenterAndDispersion/jobs/<jobId>
Access results
When the status of the job request is esriJobSucceeded, you can access the results of the analysis by making a request of the following form:
https://<analysis-url>/SummarizeCenterAndDispersion/jobs/<jobId>/results/output?token=<your token>&f=json
Response | Description |
---|---|
centralFeatureLayer | The centralFeatureLayer is optional and will only be returned when a summaryType of CentralFeature is specified. The geometry and time type of the resulting centralFeatureLayer features will be the same as the inputLayer.
The result has properties for parameter name, data type, and value. The contents of value depend on the outputName parameter provided in the initial request. The value contains the URL of the feature service layer. |
meanCenterLayer | The meanCenterLayer is optional and will only be returned when a summaryType of MeanCenter is specified. The meanCenterLayer will always be a point feature layer that represents the mean centers of the features from the inputLayer. If the inputLayer is time enabled, the result will contain the mean time value of the input data.
The result has properties for parameter name, data type, and value. The contents of value depend on the outputName parameter provided in the initial request. The value contains the URL of the feature service layer. |
medianCenterLayer | The medianCenterLayer is optional and will only be returned when a summaryType of MedianCenter is specified. The medianCenterLayer will always be a point feature layer that represents the median centers of the features from the inputLayer. If the inputLayer is time enabled, the results will contain the median time value of the input data.
The result has properties for parameter name, data type, and value. The contents of value depend on the outputName parameter provided in the initial request. The value contains the URL of the feature service layer. |
ellipseLayer | The ellipseLayer is optional and will only be returned when a summaryType of Ellipse is specified. The ellipseLayer will always be a polygon feature layer that represents standard deviational ellipses of the inputLayer. If the input layer is time enabled, the result will be time enabled with a time type of interval. The features included in calculating the start and end time values will depend on the ellipseSize parameter.
The result has properties for parameter name, data type, and value. The contents of value depend on the outputName parameter provided in the initial request. The value contains the URL of the feature service layer. |