Find Hot Spots

pointLayer (Required)

The point feature layer for which hot spots will be calculated.

Analysis using bins requires a projected coordinate system. When aggregating layers into bins, the input layer or processing extent (processSR ) must have a projected coordinate system. If a projected coordinate system is not specified when running analysis, a projection will be picked based on the extent of the data.

Syntax: As described in Feature input, this parameter can be one of the following:

• A URL to a feature service layer with an optional filter to select specific features
• A URL to a big data catalog service layer with an optional filter to select specific features
• A feature collection

REST examples

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//REST web example
{"url": "https://myportal.domain.com/server/rest/services/Hosted/hurricaneTrack/FeatureServer/0", "filter": "Month = 'September'"}

//REST scripting example
"pointLayer": {"url": "https://myportal.domain.com/server/rest/services/Hosted/hurricaneTrack/FeatureServer/0", "filter": "Month = 'September'"}

binSize (Required)

The distance for the square bins the pointLayer will be aggregated into.

REST examples

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//REST web example
108.3

//REST scripting example
"binSize": 100

binSizeUnit (Required)

The distance unit for the bins with which hot spots will be calculated. The linear unit to be used with the value specified in binSize. When generating bins the number and units specified determine the height and length of the square. The default is Meters.

Values: Meters | Kilometers | Feet | FeetInt | FeetUS | Miles |MilesInt | MilesUS | NauticalMiles | NauticalMilesInt | NauticalMilesUS | Yards | YardsInt | YardsUS

REST examples

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//REST web example
Meters

//REST scripting example
"binSizeUnit": "Miles"

neighborhoodDistance (Required)

The size of the neighborhood within which to calculate the hot spots. The radius size must be larger than binSize.

REST examples

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//REST web example
150.5

//REST scripting example
"neighborhood": 100

neighborhoodDistanceUnit (Required)

The distance unit for the radius defining the neighborhood where the hot spots will be calculated. The linear unit to be used with the value specified in binSize. The default is Meters.

Values: Meters | Kilometers | Feet | FeetInt | FeetUS | Miles |MilesInt | MilesUS | NauticalMiles | NauticalMilesInt | NauticalMilesUS | Yards | YardsInt | YardsUS

REST examples

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//REST web example
Miles

//REST scripting example
"neighborhoodUnit": "Miles"

timeStepInterval (Optional)

A numeric value that specifies duration of the time step interval. The default is none. This option is only available if the input points are time enabled and represent an instant in time.

REST examples

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//REST web example
20

//REST scripting example
"timeStepInterval": 20

timeStepIntervalUnit (Optional)

A string that specifies units of the time step interval. The default is none. This option is only available if the input points are time enabled and represent an instant in time.

REST examples

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//REST web example
Minute

//REST scripting example
"timeStepIntervalUnit": "Minutes"

timeStepAlignment (Optional)

Defines how aggregation will occur based on a given timeStepInterval. The following options are available:

• StartTime —Time is aligned to the first feature in time.
• EndTime —Time is aligned to the last feature in time.
• ReferenceTime —Time is aligned a specified time in timeStepReference.

REST examples

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//REST web example
StartTime

//REST scripting example
"timeStepAlignment": "StartTime"

timeStepReference (Required if timeStepAlignment is ReferenceTime)

A date that specifies the reference time to align the time slices to, represented in milliseconds from epoch. The default is January 1, 1970, at 12:00 a.m. (epoch time stamp 0). This option is only available if the input points are time enabled and of time type instant.

REST examples

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//REST web example
946684800000

//REST scripting example
"timeStepReference": 946684800000

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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//REST web example
myOutput

//REST scripting example
"outputName": "myOutput"

context (Optional)

The context parameter contains additional settings that affect task execution. For this task, there are four settings:

• Extent (extent )—A bounding box that defines the analysis area. Only those features that intersect the bounding box will be analyzed.
• Processing spatial reference (processSR )—The features will be projected into this coordinate system for analysis.
• Output spatial reference (outSR )—The features will be projected into this coordinate system after the analysis to be saved. The output spatial reference for the spatiotemporal big data store is always WGS84.
• Data store (dataStore )—Results will be saved to the specified data store. The default is the spatiotemporal big data store.

Syntax:

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{
  "extent": {extent},
  "processSR": {spatial reference},
  "outSR": {spatial reference},
  "dataStore": {data store}
}

f

The response format. The default response format is html .

Values: html | json | pjson

output

The result of FindHotSpots is a feature layer that provides information about statistically significant hot and cold features. The output is always polygons of the bin size specified at tool run. The result layer has the following attributes:

• GiPValue — The probability that the observed spatial pattern was created by some random process.
• GiZScore —A numeric (double) field with standard deviations representing the intensity of spatial clustering.
• Gi_Bin —Symbolizes the results. Values range from -3 to +3 and reflect statistical significance. Use blue to draw values less than zero and red to draw values greater than zero. Use the darkest blue for features equal to -3, medium blue for -2, and light blue for -1. Use the darkest red for features equal to 3, medium red for 2, and the lightest red or pink for 1. A confidence bin value of zero means no statistically significant clustering, and these features should be drawn in white or beige (the color selected should be neutral).

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{"url": "https://<analysis-url>/FindHotSpots/jobs/<jobId>/results/output"}

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.

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{
  "paramName": "output",
  "dataType": "GPRecordSet",
  "value":{"url": "<hosted featureservice layer url>"}
}

See Feature output for more information about how the result layer is accessed.