Method Overview

Method Details

summaryStatistics(params){Promise<SummaryStatisticsResult>}

Returns an object containing various statistics describing a set of values returned from a field (or expression) in a Layer.

Parameters:

params Object See the table below for details of each parameter. Specification: layer FeatureLayer|SceneLayer|CSVLayer|PointCloudLayer The layer from which to generate statistics for the given field. field String optional The name of the numeric field for which the summary statistics will be generated. This property is ignored if a valueExpression is used. valueExpression String optional An Arcade expression that returns a number. This expression can reference field values using the $feature global variable. This property overrides the field property and therefore is used instead of an input field value. sqlExpression String optional A SQL expression evaluating to a number. sqlWhere String optional A SQL where clause used to filter features for the statistics query. For example, this is useful in situations where you want to avoid dividing by zero as is the case with creating a predominance visualization. normalizationField String optional The field by which to normalize the values returned from the given field. minValue Number optional The minimum bounding value for the statistics calculation. Use this in conjunction with maxValue to generate statistics between lower and upper bounds. maxValue Number optional The maximum bounding value for the statistics calculation. Use this in conjunction with minValue to generate statistics between lower and upper bounds. view View optional A SceneView or MapView instance is required when a valueExpression is specified. features Graphic[] optional A subset of features for which to calculate the statistics.

Returns:

Type	Description
Promise<SummaryStatisticsResult>	Returns a promise that resolves to SummaryStatisticsResult.

Example:

summaryStatistics({
  layer: featureLayer,
  valueExpression: "( ($feature.POP2020 - $feature.POP2010) / $feature.POP2010 ) * 100"
  view: mapView
}).then(function(stats){
  colorSlider.statistics = stats;
});

Type Definitions

SummaryStatisticsResult

The statistics returned from the summaryStatistics() query.

Properties:

avg Number The average of all values returned from the field or expression.

count Number The number of features evaluated.

max Number The maximum of all values returned from the field or expression.

min Number The minimum of all values returned from the field or expression.

stddev Number The standard deviation calculated from values returned from the field or expression.

sum Number The sum of all values returned from the field or expression.

variance Number The calculated variance from all values returned from the field or expression.