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esri/dijit/util
esri/layer/pixelFilters
esri/process
esri/workers
Class: FindHotSpots

require(["esri/dijit/analysis/FindHotSpots"], function(FindHotSpots) { /* code goes here */ });

Description

(Added at v3.7)
The FindHotSpots widget finds statistically significant clusters of incident points, weighted points, or weighted polygons. For incident data, the analysis field (weight) is obtained by aggregation. The output is a hot spot layer, where hot spots are shown in red and cold spots in blue.

View the ArcGIS REST API documentation for the Find Hot Spots task for more details.

Samples

Search for samples that use this class.

Class hierarchy

esri/dijit/analysis/AnalysisBase
|_esri/dijit/analysis/FindHotSpots

Constructors

NameSummary
new FindHotSpots(params, srcNodeRef)Creates a new FindHotSpots dijit using the given DOM node.

CSS

esri/dijit/analysis/FindHotSpots | Download source

Properties

NameTypeSummary
aggregationPolygonLayersFeatureLayer[]
An array of feature layer candidates to be selected as the aggregation polygon layer.
analysisFieldStringThe numeric field in the AnalysisLayer that will be analyzed.
analysisGpServerStringThe URL to the analysis service, for example "http://analysis.arcgis.com/arcgis/rest/services/tasks/GPServer".
analysisLayerFeatureLayerThe feature layer for which hot spots will be calculated.
boundingPolygonLayerFeatureLayerA layer of bounding areas to answer the question: Within the bounding areas, are there any locations with unexpectedly high or low point concentrations?.
boundingPolygonLayersFeatureLayer[]An array of feature layer candidates to be selected as the bounding polygon layer.
folderIdStringSets the selected folder of the select folder dropdown, based on the provided folderId, when showSelectFolder is true.
folderNameStringSets the selected folder of the select folder dropdown, based on the provided folderName, when showSelectFolder is true.
mapMapReference to the map object.
outputLayerNameStringThe name of the output layer to be shown in the Result layer name inputbox.
portalSelfObjectThe self response of the Portal.
portalUrlStringThe URL to the ArcGIS.com site or in-house portal where the GP server is hosted, for example "http://www.arcgis.com".
returnFeatureCollectionBooleanWhen true, returns the result of analysis as a client-side feature collection.
returnProcessInfoBooleanReturn a report of the analysis process.
showChooseExtentBooleanWhen true, the choose extent checkbox will be shown.
showCloseIconBooleanIndicates whether to show the close icon on the widget's user interface.
showCreditsBooleanWhen true, the show credit option is visible.
showHelpBooleanWhen true, the help links will be shown.
showReadyToUseLayersBooleanWhen true, adds an option to the UI that allows users to choose ready to use analysis layers from the Living Atlas Analysis Layers.
showSelectAnalysisLayerBooleanIndicates whether to display a drop down menu listing valid input analysis layers.
showSelectFolderBooleanWhen true, the select folder dropdown will be shown.
titleStringOverrides the default widget title with a custom title.

Methods

NameReturn typeSummary
cancel(jobInfo)NoneCancels an analysis job that is being processed.
checkJobStatus(jobId)NoneStarts checking the analysis job status for the given jobId.
execute(params)NoneStarts an analysis tool.
getCreditsEstimate(toolName, jobParams)DeferredGets credits estimate for a specific analysis job.
startup()NoneFinalizes the creation of the widget.

Events

[ On Style Events | Connect Style Event ]
All On Style event listeners receive a single event object. Additionally, the event object also contains a 'target' property whose value is the object which fired the event.

Events

NameEvent ObjectSummary
closeFires when close icon is clicked or when run analysis button is clicked.
drawtool-activateFires when the drawn boundaries option is activated.
drawtool-deactivateFires when the drawn boundaries option is deactivated.
job-cancel
{
  response: <Object>
}
Fires when the job in cancelled.
job-fail
{
  error: <Object>
}
Fires when the job fails.
job-result
{
  result: <Object>
}
Fires after the job fetches result data.
job-status
{
  jobInfo: <Object>
}
Fires when the job execution status is received.
job-submit
{
  params: <Object>
}
Fires when the job is submitted to the server for asynchronous processing.
job-success
{
  jobInfo: <Object>
}
Fires when the job succeeds.
start
{
  params: <Object>
}
Fires when the execute method is called.
Constructor Details

new FindHotSpots(params, srcNodeRef)

Creates a new FindHotSpots dijit using the given DOM node.
Parameters:
<Object> params Required Various options to configure this dijit. Refer to the Options table below.
<Node | String> srcNodeRef Required Reference or id of a HTML element that this dijit is rendered into.
params properties:
<FeatureLayer[]> aggregationPolygonLayers Required An array of feature layer candidates to be selected as the aggregation polygon layer. The aggregation polygon layer defines the boundaries within which incidents will be aggregated before analysis. When this layer is specified, the number of incidents within each polygon will be counted. These polygons with their incident counts will be used as the input features for analysis. The geometry of output hot spots layer will also be based on these polygons.

For example, if you are analyzing traffic accidents in a city and the outlines of census tracts in that city are selected as bounding polygons, the output hot spots value will be based on each census tract instead of each accident's location.

This parameter should be used only when analysisLayer is a point layer. It will be shown as an option under Choose an analysis field. This option is available only when analysisField is not selected.

* Required.
<String> analysisField Optional The numeric field in the AnalysisLayer that will be analyzed. When the AnalysisLayer is a point FeatureLayer, rather than a field name the AnalysisField may be "NO ANALYSIS FIELD".
<String> analysisGpServer Optional The URL to the GPServer used to execute an analysis job.

* Required when portalUrl is not specified.
<FeatureLayer> analysisLayer Required The feature layer for which hot spots will be calculated. Can be a polygon or a point layer.

* Required.
<FeatureLayer[]> boundingPolygonLayers Required An array of feature layer candidates to be selected as the bounding polygon layer. The bounding polygon layer defines the study area within which incidents could have occurred. When this layer is specified, all locations within this layer will be analyzed, whether any incident occurred at a location or not. When not specified, only locations with at least one point (incident) will be included in the analysis.

For example, if you are analyzing boating accidents in a harbor, the outline of the harbor might provide a good boundary for where accidents could occur. When no bounding areas are provided, only locations with at least one point will be included in the analysis.

This parameter should be used only when the analysisLayer is a point layer. It will be shown as an option under Choose an analysis field. This option is available only when analysisField is not selected.

* Required.
<Boolean> isProcessInfo Optional When true, make process info to get analysis report.
<Map> map Optional Reference to the map object.

* Required when showChooseExtent is true.
<String> outputLayerName Optional The name of the output layer to be shown in the Result layer name inputbox. If not specified, "Hot Spots ${analysis_layer_title}" will be shown by default.
<String> portalUrl Optional The url to the ArcGIS.com site or in-house portal where the GP server is hosted.

* Required when analysisGpServer is not specified.
<Boolean> returnFeatureCollection Optional When true, returns the result of analysis as a client-side feature collection. This value determines whether or not the result will be saved and published on a user's arcgis.com account.
<Boolean> showChooseExtent Optional When true, the choose extent checkbox will be shown.
<Boolean> showCredits Optional When true, the show credit option is visible.
<Boolean> showHelp Optional When true, the help links will be shown.
<Boolean> showSelectFolder Optional When true, the select folder dropdown will be shown. This parameter should be used when you want to allow users to select a folder in their arcgis.com account where the output feature layer will be exported as a service. When returnFeatureCollection is set to true, this option becomes invalid since no arcgis.com item will be created.
Sample:
require(["esri/dijit/analysis/FindHotSpots", ... ], function(FindHotSpots, ... ){
  var findHotSpots = new FindHotSpots({
    analysisLayer: inputlayer,
    boundingPolygonLayers: polygonLayers,
    aggregationPolygonLayers: polygonLayers,
    map: map,
    portalUrl: "http://www.arcgis.com"
  }, "analysis-tool");
});
Property Details

<FeatureLayer[]> aggregationPolygonLayers

An array of feature layer candidates to be selected as the aggregation polygon layer. The aggregation polygon layer defines the boundaries within which incidents will be aggregated before analysis. When this layer is specified, the number of incidents within each polygon will be counted. These polygons with their incident counts will be used as the input features for analysis. The geometry of output hot spots layer will also be based on these polygons.

For example, if you are analyzing traffic accidents in a city and the outlines of census tracts in that city are selected as bounding polygons, the output hot spots value will be based on each census tract instead of each accident's location.

This parameter should be used only when analysisLayer is a point layer. It will be shown as an option under Choose an analysis field. This option is available only when analysisField is not selected.

<String> analysisField

The numeric field in the AnalysisLayer that will be analyzed. When the AnalysisLayer is a point FeatureLayer, rather than a field name the AnalysisField may be "NO ANALYSIS FIELD".

<String> analysisGpServer

The URL to the analysis service, for example "http://analysis.arcgis.com/arcgis/rest/services/tasks/GPServer".

<FeatureLayer> analysisLayer

The feature layer for which hot spots will be calculated. Can be a polygon or a point layer.

<FeatureLayer> boundingPolygonLayer

A layer of bounding areas to answer the question: Within the bounding areas, are there any locations with unexpectedly high or low point concentrations? (Added at v3.12)

<FeatureLayer[]> boundingPolygonLayers

An array of feature layer candidates to be selected as the bounding polygon layer. The bounding polygon layer defines the study area within which incidents could have occurred. When this layer is specified, all locations within this layer will be analyzed, whether any incident occurred at a location or not. When not specified, only locations with at least one point (incident) will be included in the analysis.

For example, if you are analyzing boating accidents in a harbor, the outline of the harbor might provide a good boundary for where accidents could occur. When no bounding areas are provided, only locations with at least one point will be included in the analysis.

This parameter should be used only when the analysisLayer is a point layer. It will be shown as an option under Choose an analysis field. This option is available only when analysisField is not selected.

<String> folderId

Sets the selected folder of the select folder dropdown, based on the provided folderId, when showSelectFolder is true. When folderId and folderName are both provided, folderId has higher precedence. (Added at v3.13)

<String> folderName

Sets the selected folder of the select folder dropdown, based on the provided folderName, when showSelectFolder is true. (Added at v3.13)

<Map> map

Reference to the map object.

<String> outputLayerName

The name of the output layer to be shown in the Result layer name inputbox. If not specified, "Hot Spots ${analysis_layer_title}" will be shown by default.

<Object> portalSelf

The self response of the Portal. When set, optimizes performance to reuse self calls made by the widget. For more documentation on the properties of this object, see the Portal Self ArcGIS REST API documentation. (Added at v3.14)

<String> portalUrl

The URL to the ArcGIS.com site or in-house portal where the GP server is hosted, for example "http://www.arcgis.com". (Added at v3.7)

<Boolean> returnFeatureCollection

When true, returns the result of analysis as a client-side feature collection. This value determines whether or not the result will be saved and published on a user's arcgis.com account.
Known values: true | false
Default value: false

<Boolean> returnProcessInfo

Return a report of the analysis process. (Added at v3.12)
Known values: true | false
Default value: true

<Boolean> showChooseExtent

When true, the choose extent checkbox will be shown.
Known values: true | false
Default value: true

<Boolean> showCloseIcon

Indicates whether to show the close icon on the widget's user interface. (Added at v3.14)
Known values: true | false
Default value: true

<Boolean> showCredits

When true, the show credit option is visible.
Known values: true | false
Default value: true

<Boolean> showHelp

When true, the help links will be shown.
Known values: true | false
Default value: true

<Boolean> showReadyToUseLayers

When true, adds an option to the UI that allows users to choose ready to use analysis layers from the Living Atlas Analysis Layers. (Added at v3.14)
Known values: true | false
Default value: true

<Boolean> showSelectAnalysisLayer

Indicates whether to display a drop down menu listing valid input analysis layers. (Added at v3.14)
Known values: true | false
Default value: true

<Boolean> showSelectFolder

When true, the select folder dropdown will be shown. This parameter should be used when you want to allow users to select a folder in their arcgis.com account where the output feature layer will be exported as a service.
Known values: true | false
Default value: false

<String> title

Overrides the default widget title with a custom title. Set this value in the initial constructor parameters.

For example, instead of using the default title (e.g. "Find Hot Spots"), you can use this property to change the default to a customized title for the tool (e.g. "Areas with High Crime"). (Added at v3.14)
Method Details

cancel(jobInfo)

Cancels an analysis job that is being processed.
Parameters:
<Object> jobInfo Required An object containing job information including job ID, status, message, etc returned by the job-status event.

checkJobStatus(jobId)

Starts checking the analysis job status for the given jobId. (Added at v3.12)
Parameters:
<String> jobId Required Job id of the analysis job to check.

execute(params)

Starts an analysis tool.
Parameters:
<String> params Required See the object specifications table below for the structure of the params object.
Object Specifications:
<params>
<Object> itemParams Optional Parameters for creating the output service item. Refer to the ArcGIS REST API - Add Item help topic for a list of available parameters. Only used when the analysis task creates a hosted service.
<Object> jobParams Required The input job parameters. Required parameters vary from class to class. Refer to the Analysis REST API Documentation for details (Under the Request Parameters section of each task). When creating a hosted service, a layer name is required.
Sample:
var params = {
  itemParams: {
    description: "Item description.",
    snippet: "A short summary about this item.",
    tags: "<tag1>, <tag2>, <tag3>, ... ",
    typeKeywords: "<typeKeyword1>, <typeKeyword2>, <typeKeyword3>, ... "
  },
  jobParams: {
    outputLayerName: "{\"serviceProperties\":{\"name\":\"Name of the output feature service\"},\"itemProperties\":{\"itemId\":\"<itemId>\"}}",
    ...
  }
}

analysisBase.execute(params);

getCreditsEstimate(toolName, jobParams)

Gets credits estimate for a specific analysis job. This method returns a deferred object. The callback function has an object containing the number of records to be processed and the estimated credit cost for this job.
Return type: Deferred
Parameters:
<String> toolName Required The name of the analysis tool from which a credits estimate will be returned.
<String> jobParams Required The input job parameters. This value should be the same as the jobParams property of an analysis tool dijit. Refer to the jobParams property of this class for detailed syntax.
Sample:
analysisBase.getCreditsEstimate("FindHotSpots",{
  AnalysisLayer: layer._json,
  context: '{"outSR":{"wkid":102100}}',
  isProcessInfo: true,
  returnFeatureCollection: true
}).then(function(result){
  console.log(result);
});

//the "result" argument above:
//{
//  "cost": 1.472,
//  "totalRecords": 1472,
//}

startup()

Finalizes the creation of the widget. (Added at v3.12)
Event Details
[ On Style Events | Connect Style Event ]

close

Fires when close icon is clicked or when run analysis button is clicked. (Added at v3.7)

drawtool-activate

Fires when the drawn boundaries option is activated. Only valid when using the FindHotSpots or ExtractData widget. A typical usage is to disable the zoom/pan/popup handlers when drawing is activated. (Added at v3.7)

drawtool-deactivate

Fires when the drawn boundaries option is deactivated. Only valid when using the FindHotSpots or ExtractData widget. A typical usage is to enable the zoom/pan/popup handlers when drawing is deactivated. (Added at v3.7)

job-cancel

Fires when the job in cancelled. (Added at v3.7)
Event Object Properties:
<Object> response An GP job object returned by the GP server. Refer to the GP Job and the Checking job status topics in the ArcGIS REST API Documentation for more information and syntax.
{
  "inputs": {},
  "jobId": <job id>,
  "jobStatus": <job status>,
  "messages": <an array of message text>,
  "results": {}
}

job-fail

Fires when the job fails. (Added at v3.7)
Event Object Properties:
<Object> error The error message returned by a failed job.
{
  "analysisReport": <analysis report message>,
  "dataType": <analysis report message>,
  "paramName": < parameter  name >,
  "value": <output item info | feature collection>
}

job-result

Fires after the job fetches result data. The returned argument contains the output value (either a feature collection or a url to the hosted service), which you may add to the map as a feature layer. (Added at v3.7)
Event Object Properties:
<Object> result An object containing the resulted message and value. Based on the GP result object returned by the GP server with the analysisReport property added.

If output is a feature collection, value is a feature collection object; if output is a hosted arcgis.com feature service, value is an object with item information including ID and URL. Refer to the ArcGIS REST API documentation - Feature Output for more information.
{
  "analysisReport": <analysis report message>,
  "dataType": <analysis report message>,
  "paramName": < parameter  name >,
  "value": <output item info | feature collection>
}
Sample:
analysisTool.on("job-result", function(result){
  var featureLayer = new FeatureLayer(result.value['url'] || result.value);
  map.addLayer(featureLayer);
})

job-status

Fires when the job execution status is received. (Added at v3.7)
Event Object Properties:
<Object> jobInfo An object containing job information including job ID, status, message, etc. Based on the GP job object returned by the GP server with the jobParam property attached. Refer to the GP Job and the Checking job status topics in the ArcGIS REST API Documentation for more information and syntax.
{
  "inputs": {},
  "jobParams": <job parameters>,
  "jobId": <job id>,
  "jobStatus": <job status>,
  "messages": <an array of message text>,
  "results": {}
}

job-submit

Fires when the job is submitted to the server for asynchronous processing. (Added at v3.7)
Event Object Properties:
<Object> params The input job parameters.

job-success

Fires when the job succeeds. (Added at v3.7)
Event Object Properties:
<Object> jobInfo An object containing job information including job ID, status, message, etc. Based on the GP job object returned by the GP server with the jobParam property attached. Refer to the GP Job and the Checking job status topics in the ArcGIS REST API Documentation for more information and syntax.

This returned object can be passed into the .cancel(jobInfo) method to terminate a job.
{
  "inputs": {},
  "jobParams": <job parameters>,
  "jobId": <job id>,
  "jobStatus": <job status>,
  "messages": <an array of message text>,
  "results": {}
}

start

Fires when the execute method is called. (Added at v3.7)
Event Object Properties:
<Object> params The input job parameters.