The size visual variable defines the size of individual features in a layer based on a numeric (often thematic) value. This value comes from one of the following:

• An attribute field
• The value of an attribute field divided by a normalizationField
• A value returned from an Arcade expression specified in valueExpression.

Size is defined in the form of a continuous ramp, which may be applied to renderers in either a MapView or a SceneView.

Symbol size may be applied either thematically, or literally using real-world units. See the following object specification tables for details about each potential use of a size visual variable:

• BoundedMinMax - Feature sizes are bounded by min and max data values. Intermediate values are linearly interpolated between the minSize and maxSize.
• ThematicStops - Defines between two and six stops at which feature sizes are mapped to data values.
• ScaleDependentIcons - Icon sizes are bounded by min and max data values, but the minSize and maxSize (and interpolated sizes) change based on the scale of the MapView.
• ScaleDependentStops - Defines the width of polygon outlines at various view scales.
• RealWorldSize - Feature sizes are determined based on real-world measurements and units, not thematic values and screen units.

Thematic Icon size	Thematic extrusion	Real world size

See also:

• Sample - Continuous size

• Sample - Visualize features thematically with extrusion

• Sample - Scale feature sizes based on real world sizes (2D)

• Sample - Visualize features with realistic 3D symbols

• Sample - Extrude building footprints based on real world heights

Examples:

// Bounded min/max visual variable (similar to proportional size)
const sizeVisualVariable = {
  type: "size",
  field: "WIND_SPEED",
  minDataValue: 0,
  maxDataValue: 60,
  minSize: 8,
  maxSize: 40
};
renderer.visualVariables = [ sizeVisualVariable ];

// Thematic stops variable (similar to proportional size)
renderer.visualVariables = [{
  type: "size",
  field: "POP_POVERTY",
  normalizationField: "TOTPOP_CY",
  legendOptions: {
    title: "% population in poverty by county"
  },
  stops: [
    { value: 0.15, size: 4, label: "<15%" },
    { value: 0.25, size: 12, label: "25%" },
    { value: 0.35, size: 24, label: ">35%" }
  ]
}];

// Real world size for 3D objects
const treeSizeVisualVariables = [{
  type: "size",
  axis: "height",
  field: "Height", // tree height
  valueUnit: "feet"
}, {
  type: "size",
  axis: "width",
  field: "Width_EW", // crown diameter from east to west
  valueUnit: "feet"
}, {
  type: "size",
  axis: "depth",
  field: "Width_NS", // crown diameter from north to south
  valueUnit: "feet"
}];
renderer.visualVariables = treeSizeVisualVariables;

Constructors

new SizeVariable(properties)

Parameter:

properties Object optional See the properties for a list of all the properties that may be passed into the constructor.

Property Overview

Property Details

axisString

Only applicable when working in a SceneView. Defines the axis the size visual variable should be applied to when rendering features with an ObjectSymbol3DLayer. See the local scene sample for an example of this.

Possible Value	Description
width	The diameter of the symbol from east to west.
depth	The diameter of the symbol from north to south.
height	The height of the symbol.
width-and-depth	Applies the size visual variable to both width and depth axes.
all	Applies the size visual variable to all axes.

Default Value:all

See also:

• RealWorldSize

declaredClassStringreadonly inherited

The name of the class. The declared class name is formatted as esri.folder.className.

expressionString

Deprecated

• Deprecated since version 4.2

Deprecated. Use valueExpression instead**. The only supported expression is view.scale.

fieldString inherited

The name of the numeric attribute field that contains the data values used to determine the color/opacity/size/rotation of each feature.

indexString|Number inherited

The index of the visual variable in relation to its position in the visualVariables property of the renderer.

legendOptionsObject

An object providing options for displaying the visual variable in the Legend.

Properties:

customValues Number[] optional Overrides the legend values with values specified here. This is typically used to round values interpolated from the SizeVariable to rounded numbers.

showLegend Boolean optional Indicates whether to show the visual variable in the legend.

title String optional The title describing the visualization of the visual variable in the Legend. This takes precedence over a field alias or valueExpressionTitle.

maxDataValueNumber

The maximum data value used in the size ramp. Features whose field or valueExpression return a value equal to or higher than the value defined in maxDataValue will be rendered at the size defined in maxSize.

maxSizeNumber|ScaleDependentStopsautocast

Autocasts from String|Object

The size used to render a feature containing the maximum data value.

• When setting a number, sizes are expressed in points for all 2D symbols and 3D flat symbol layers; size is expressed in meters for all 3D volumetric symbols.
• String values are only supported for 2D symbols and 3D flat symbol layers. Strings may specify size in either points or pixels (e.g. minSize: "16pt", minSize: "12px").
• When an object is used, the size of features whose data value (defined in field or valueExpression) is greater than or equal to the maxDataValue for the given view scale.

minDataValueNumber

The minimum data value used in the size ramp. Features whose field or valueExpression return a value equal to or lower than the value defined in maxDataValue will be rendered at the size defined in minSize.

minSizeNumber|ScaleDependentStopsautocast

Autocasts from String|Object

The size used to render a feature containing the minimum data value.

• When setting a number, sizes are expressed in points for all 2D symbols and 3D flat symbol layers; size is expressed in meters for all 3D volumetric symbols.
• String values are only supported for 2D symbols and 3D flat symbol layers. Strings may specify size in either points or pixels (e.g. minSize: "16pt", minSize: "12px").
• When an object is used, the size of features whose data value (defined in field or valueExpression) is greater than or equal to the minDataValue for the given view scale.

normalizationFieldString

The name of the numeric attribute field used to normalize the data in the given field. If this field is used, then the values in maxDataValue and minDataValue or stops should be normalized as percentages or ratios.

stopsSizeStop[]autocast

Autocasts from Object[]

An array of objects that defines the mapping of data values returned from field or valueExpression to icon sizes. You must specify 2 - 6 stops. The stops must be listed in ascending order based on the value of the value property in each stop.

targetString

This value must be outline when scaling polygon outline widths based on the view scale. If scale-dependent icons are desired, then this property should be ignored.

See also:

• ScaleDependentStops

typeStringreadonly

The visual variable type. For SizeVariable, this value is always size.

useSymbolValueBoolean

When setting a size visual variable on a renderer using an ObjectSymbol3DLayer, this property indicates whether to apply the value defined by the height, width, or depth properties to the corresponding axis of this visual variable instead of proportionally scaling this axis' value. View an example of this.

valueExpressionString inherited

An Arcade expression evaluating to a number. This expression can reference field values using the $feature global variable and perform mathematical calculations and logical evaluations at runtime. The values returned from this expression are the data used to drive the visualization. This takes precedence over field. Therefore, this property is typically used as an alternative to field in visual variables.

See also:

• Arcade - expression language

valueExpressionTitleString inherited

The title identifying and describing the associated Arcade expression as defined in the valueExpression property. This is displayed as the title of the corresponding visual variable in the Legend in the absence of a provided title in the legendOptions property.

valueRepresentationString

Specifies how to apply the data value when mapping real-world sizes. See table below for supported values.

Value	Description
radius	The point data value represents the radius of a circular feature.
diameter	The point data value represents the diameter of a circular feature.
area	The point data value represents the area of a feature.
width	The polyline data value represents the width of a line.
distance	The polyline data value represents the distance from the center line (one half of the width).

valueUnitString

Indicates the unit of measurement used to interpret the value returned by field or valueExpression. For 3D volumetric symbols the default is meters. This property should not be used if the data value represents a thematic quantity (e.g. traffic count, census data, etc.).

Possible Values: unknown | inches | feet | yards | miles | nautical-miles | millimeters | centimeters | decimeters | meters | kilometers | decimal-degrees

See also:

• RealWorldSize

Method Overview

Method Details

clone(){SizeVariable}

Creates a deep clone of the SizeVisualVariable.

Returns:

Type	Description
SizeVariable	A deep clone of the size visual variable that invoked this method.

Example:

// Creates a deep clone of the visual variable
var renderer = renderer.visualVariables[0].clone();

fromJSON(json){*}static

Creates a new instance of this class and initializes it with values from a JSON object generated from a product in the ArcGIS platform. The object passed into the input json parameter often comes from a response to a query operation in the REST API or a toJSON() method from another ArcGIS product. See the Using fromJSON() topic in the Guide for details and examples of when and how to use this function.

Parameter:

json Object A JSON representation of the instance in the ArcGIS format. See the ArcGIS REST API documentation for examples of the structure of various input JSON objects.

Returns:

Type	Description
*	Returns a new instance of this class.

toJSON(){Object}

Converts an instance of this class to its ArcGIS portal JSON representation. See the Using fromJSON() topic in the Guide for more information.

Returns:

Type	Description
Object	The ArcGIS portal JSON representation of an instance of this class.

Type Definitions

BoundedMinMax

Defines a size visual variable with minimum and maximum bounds. When an object with this specification is applied to the visualVariables property of a renderer, then feature sizes are bounded by min and max data values. Features with values greater than the provided max value are assigned the specified maximum size. Likewise, features with values less than the provided min value are assigned the specified minimum size. Features with values between the min and the max are assigned a corresponding size that is linearly interpolated between the min and max size values.

The properties for this size visual variable type are defined below.

Properties:

type String Value must be size.

field String optional See field.

normalizationField String optional See normalizationField.

valueExpression String optional See valueExpression.

valueExpressionTitle String optional See valueExpressionTitle.

maxDataValue Number See maxDataValue.

maxSize String|Number The size used to render a feature containing the maximum data value. When setting a number, sizes are expressed in points for all 2D symbols and 3D flat symbol layers; size is expressed in meters for all 3D volumetric symbols. String values are only supported for 2D symbols and 3D flat symbol layers. Strings may specify size in either points or pixels (e.g. minSize: "16pt", minSize: "12px").

minDataValue Number See minDataValue.

minSize String|Number The size used to render a feature containing the minimum data value. When setting a number, sizes are expressed in points for all 2D symbols and 3D flat symbol layers; size is expressed in meters for all 3D volumetric symbols. String values are only supported for 2D symbols and 3D flat symbol layers. Strings may specify size in either points or pixels (e.g. minSize: "16pt", minSize: "12px").

Examples:

// thematic size defined with min and max data values
const sizeVisVar = {
  type: "size",
  field: "POPULATION",
  // features with this value or lower will be assigned the size defined in minSize
  minDataValue: 5000,
  // features with this value or higher will be assigned the size defined in maxSize
  maxDataValue: 1000000,
  minSize: "6px",
  maxSize: "80px"
};
renderer.visualVariables = [ sizeVisVar ];

// 3D thematic extrusion
const sizeVisVar = {
  type: "size",
  field: "POP_POVERTY",
  normalizationField: "TOTPOP_CY",
  minDataValue: 0.10,  // 10% of population in poverty
  maxDataValue: 0.35,  // 35% of population in poverty
  minSize: 10000,  // extruded by 10,0000 meters
  maxSize: 500000  // extruded by 500,000 meters
};
renderer.visualVariables = [ sizeVisVar ];

RealWorldSize

Defines a size visual variable where data values are interpreted as real-world sizes based on a given unit. Features are then sized according to the real-world measurements, not thematic values and screen units.

The object specification for this object is provided below.

Properties:

type String Value must be size.

field String optional See field.

normalizationField String optional See normalizationField.

valueExpression String optional See valueExpression.

valueUnit String See valueUnit.

valueRepresentation String optional See valueRepresentation.

See also:

• Sample - Scale feature sizes based on real world sizes (2D)

• Sample - Extrude building footprints based on real world heights

Examples:

// real-world size for 3D buildings
const sizeVisVar = {
  // The type must be set to size
  type: "size",
  // Assign the field name to visualize with size
  field: "HEIGHT",
  valueUnit: "feet"
};
renderer.visualVariables = [ sizeVisVar ];

// real-world size for 2D tree canopies
const sizeVisVar = {
  // The type must be set to size
  type: "size",
  // Assign the field name to visualize with size
  field: "CANOPY",
  valueUnit: "feet",
  valueRepresentation: "diameter"
};
renderer.visualVariables = [ sizeVisVar ];

ScaleDependentIcons

Defines icon sizes in a size visual variable based on minimum and maximum bounds similar to the BoundedMinMax case. However, this specification allows the developer to specify various min and max sizes based on the MapView.scale.

Features with values greater than the provided max value are assigned the specified maximum size for the given view scale. Likewise, features with values less than the provided min value are assigned the specified minimum size for the given view scale. Features with values between the min and the max are assigned a corresponding size linearly interpolated between the provided min and max size values for the given scale value.

The object specification for this object is provided below.

Known Limitations

Scale-dependent size visual variables are currently not supported in SceneView.

Properties:

type String Value must be size.

field String optional See field.

normalizationField String optional See normalizationField.

valueExpression String optional This value must be $view.scale.

expression String optional Deprecated since version 4.2. Use valueExpression instead. The only supported expression is view.scale.

maxDataValue Number See maxDataValue.

maxSize ScaleDependentStops An object defining the size of features whose data value (defined in field or valueExpression) is greater than or equal to the maxDataValue for the given view scale.

minDataValue Number See minDataValue.

minSize ScaleDependentStops An object defining the size of features whose data value (defined in field or valueExpression) is less than or equal to the minDataValue for the given view scale.

See also:

• Sample - Create a FeatureLayer with client side graphics

Example:

// scale-dependent size
const sizeVisVar = {
  type: "size",
  field: "pop2000",
  minDataValue: 500000,
  maxDataValue: 33000000,
  // minimum size to render minDataVal at specified view scales
  minSize: {
    type: "size",
    valueExpression: "$view.scale",
    stops: [
     { value: 1128,      size: 12 },  // smallest marker will be 12pt at 1:1128 scale
     { value: 288895,    size: 12 },
     { value: 73957191,  size: 7 },
     { value: 591657528, size: 1.5 }  // smallest marker will be 1.5pt at 1:591657528 scale
   ]
 },
 // maximum size to render maxDataVal at specified view scales
 maxSize: {
   type: "size",
   valueExpression: "$view.scale",
   stops: [
     { value: 1128,      size: 60 },  // largest marker will be 60pt at 1:1128 scale
     { value: 288895,    size: 60 },
     { value: 73957191,  size: 37 },
     { value: 591657528, size: 19 }  // largest marker will be 19pt at 1:591657528 scale
   ]
 }
};
renderer.visualVariables = [ sizeVisVar ];

ScaleDependentStops

Defines feature sizes and outline widths in a size visual variable based on the MapView.scale. It also provides the specification of the minSize and maxSize properties in a ScaleDependentIcons size visual variable.

The object specification for this object is provided below.

Known Limitations

Scale-dependent size visual variables are currently not supported in SceneView.

Properties:

type String Value must be size.

valueExpression String This value must be $view.scale.

expression String optional Deprecated since version 4.2. Use valueExpression instead. The only supported expression is view.scale.

target String optional This value must be outline when scaling polygon outline widths based on the view scale. If scale-dependent icons are desired, then this property should be ignored.

stops SizeStop[] An array of objects that define the size of the icon (or alternatively the width of the polygon outline) at the given scale value. You must specify 2 - 6 stops. The stops must be listed in ascending order based on the value of the value property in each stop. When the MapView.scale equals the value in a stop, then icons (or outlines) will be rendered with the corresponding size.

See also:

• Sample - Create a FeatureLayer with client side graphics

Example:

// scale-dependent size
const sizeVisVar = {
  type: "size",
  field: "pop2000",
  minDataValue: 500000,
  maxDataValue: 33000000,
  // minimum size to render minDataVal at specified view scales
  minSize: {
    type: "size",
    valueExpression: "$view.scale",
    stops: [
     { value: 1128,      size: 12 },  // smallest marker will be 12pt at 1:1128 scale
     { value: 288895,    size: 12 },
     { value: 73957191,  size: 7 },
     { value: 591657528, size: 1.5 }  // smallest marker will be 1.5pt at 1:591657528 scale
   ]
 },
 // maximum size to render maxDataVal at specified view scales
 maxSize: {
   type: "size",
   valueExpression: "$view.scale",
   stops: [
     { value: 1128,      size: 60 },  // largest marker will be 60pt at 1:1128 scale
     { value: 288895,    size: 60 },
     { value: 73957191,  size: 37 },
     { value: 591657528, size: 19 }  // largest marker will be 19pt at 1:591657528 scale
   ]
 }
};
renderer.visualVariables = [ sizeVisVar ];

ThematicStops

Defines two or more stops at which feature sizes are mapped to data values in a size visual variable. Setting two stops will have the same effect as creating a BoundedMinMax size visual variable. Adding additional stops allows you to map specific sizes to data values. Sizes are interpolated linearly between stop values.

The object specification for this object is provided below.

Properties:

type String Value must be size.

field String optional See field.

normalizationField String optional See normalizationField.

valueExpression String optional See valueExpression.

stops SizeStop[] An array of objects defining the thematic size ramp in a sequence of data or expression stops. At least two stops are required. The stops must be listed in ascending order based on the value of the value property in each stop.

See also:

• Sample - Continuous size

• Sample - Visualize features thematically with extrusion

Examples:

const sizeVisVar = {
  type: "size",
  field: "POPULATION",
  stops: [
    { value: 5000, size: "6px" },
    { value: 1000000, size: "80px" }
  ]
};
renderer.visualVariables = [ sizeVisVar ];

const sizeVisVar = {
  type: "size",
  valueExpression: "( $feature.TOT_VOTES / $feature.REG_VOTERS ) * 100",
  stops: [
    { value: 30, size: "6px" },
    { value: 70, size: "60px" }
  ]
};
renderer.visualVariables = [ sizeVisVar ];