com.esri.arcgis.carto
Interface IClassBreaksRenderer

All Superinterfaces:

Serializable

All Known Implementing Classes:

ClassBreaksRenderer, NetworkTrafficRenderer

public interface IClassBreaksRenderer
extends Serializable

Provides access to members that control a renderer which is used to draw graduated color (choropleth) and graduated symbol maps.

Description

IClassBreaksRenderer defines the parameters for drawing features based on the values of a quantitative attribute that is statistically grouped by a classification algorithm.

Remarks

To set up a ClassBreaksRenderer you first need to know how many classes you will have. You can decide this arbitrarily, or you can pass a proposed number of class breaks to a classification object and then have it return a valid number of breaks for your data and the classification method that you chose. To learn more see IClassifyGen. Set the number of class breaks using BreakCount.

Once BreakCount is set, the Break, Description, Label, and Symbol array properties are initialized with a lower index index of 0 and an upper index of BreakCount -1.

The next step is to set the values in Break, which are referred to as the class breaks. These values define the classes. Before setting your class breaks, you should understand the characteristics of your data. One possibility is that you may have predefined class breaks in mind, for example you might classify temperature data into 10 classes of 10 degrees each.

More commonly, you will apply a particular classification algorithm (e.g. natural breaks, quantile, equal interval) to your data and use the breaks generated from the algorithm to assign to your renderer. The easiest way to do this is to use a histogram object such as a TableHistogram, and a classification object such as NaturalBreaks. To learn more, see IClassifyGEN.

Once you have decided on your breaks, assign them to your renderering using the Break array property. You should set MinimumBreak to the lowest value in the data that you want to symbolize, and then Break(i) represents the highest value in the ith class. Values less than or equal to Break(i) but greater than Break(i-1) will be drawn with Symbol(i). To learn more see Break and Symbol.

When To Use

Use this interface to make changes to the drawing properties of a ClassBreaksRenderer.

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

See Also:

StandardDeviation, EqualInterval, NaturalBreaks, ClassBreaksRenderer, DefinedInterval, Quantile

Method Summary

IFillSymbol	getBackgroundSymbol() Background fill symbol used when graduated marker symbols are draw on polygon features.
double	getBreak(int index) Break value at the specified index.
int	getBreakCount() Number of class breaks (equal to the number of classes).
String	getDescription(int index) Description at the specified index.
String	getField() Classification field.
String	getLabel(int index) Label at the specified index.
double	getMinimumBreak() Minimum break, i.e.
String	getNormField() Normalization field.
ISymbol	getSymbol(int index) Symbol at the specified index (used to draw features in the specified class).
boolean	isSortClassesAscending() Indicates if classes are displayed in increasing order in legends/TOC.
void	setBackgroundSymbol(IFillSymbol sym) Background fill symbol used when graduated marker symbols are draw on polygon features.
void	setBreak(int index, double value) Break value at the specified index.
void	setBreakCount(int valueCount) Number of class breaks (equal to the number of classes).
void	setDescription(int index, String text) Description at the specified index.
void	setField(String field) Classification field.
void	setLabel(int index, String label) Label at the specified index.
void	setMinimumBreak(double value) Minimum break, i.e.
void	setNormField(String field) Normalization field.
void	setSortClassesAscending(boolean ascending) Indicates if classes are displayed in increasing order in legends/TOC.
void	setSymbol(int index, ISymbol sym) Symbol at the specified index (used to draw features in the specified class).

Method Detail

getBreakCount

int getBreakCount()
                  throws IOException,
                         AutomationException

Number of class breaks (equal to the number of classes).

Description

BreakCount is the number of class breaks which is equal to the number of classes in which the features are grouped for symbolization.

Remarks

Increasing this property preserves existing breaks, but decreasing it removes excess break values.

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Supported Platforms

Windows, Solaris, Linux

Returns:

The valueCount

Throws:

IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.

setBreakCount

void setBreakCount(int valueCount)
                   throws IOException,
                          AutomationException

Number of class breaks (equal to the number of classes).

Description

BreakCount is the number of class breaks (not the number of classes) that will be used to divide the data of classification Field .

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Supported Platforms

Windows, Solaris, Linux

Parameters:

valueCount - The valueCount (in)

Throws:

IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.

getField

String getField()
                throws IOException,
                       AutomationException

Classification field.

Description

Field that contains the values upon which the symbolization is based. This is the Value Field on the user interface.

Remarks

This field must be numeric.

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Supported Platforms

Windows, Solaris, Linux

Returns:

The field

Throws:

IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.

setField

void setField(String field)
              throws IOException,
                     AutomationException

Classification field.

Description

Field is the field that contains the values that will be classified.

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Supported Platforms

Windows, Solaris, Linux

Parameters:

field - The field (in)

Throws:

IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.

getNormField

String getNormField()
                    throws IOException,
                           AutomationException

Normalization field.

Description

NormField is the field that contains the values that the Field values will be divided by to produce the symbolization.

Remarks

Normalizing, i.e. dividing, by a field is the most common way to normalize data for a ClassBreaksRenderer. In general, mapping of ratios or densities is preferrable to mapping counts and a NormField can be used to generate these types of values. Normalize by an area field to represent a density, or normalize by another field with the same units as the values in Field to produce a rate. For example, to map a rate set Field to a field that stores the count of hispanic persons, and set NormField to a field that stores total persons.

Setting NormField is the same as setting IDataNormalization::NormalizationField and setting IDataNormalization::NormalizationType to esriNormalizeByField. You can use IDataNormalization to do other types of normalization.

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Supported Platforms

Windows, Solaris, Linux

Returns:

The field

Throws:

IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.

setNormField

void setNormField(String field)
                  throws IOException,
                         AutomationException

Normalization field.

Description

NormField is the field that contains the values that the classification field will be divided by when the IClassify object generates class breaks.

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Supported Platforms

Windows, Solaris, Linux

Parameters:

field - The field (in)

Throws:

IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.

getSymbol

ISymbol getSymbol(int index)
                  throws IOException,
                         AutomationException

Symbol at the specified index (used to draw features in the specified class).

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Parameters:

index - The index (in)

Returns:

A reference to a com.esri.arcgis.display.ISymbol

Throws:

IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.

setSymbol

void setSymbol(int index,
               ISymbol sym)
               throws IOException,
                      AutomationException

Symbol at the specified index (used to draw features in the specified class).

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Parameters:

index - The index (in)

sym - A reference to a com.esri.arcgis.display.ISymbol (in)

Throws:

IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.

getLabel

String getLabel(int index)
                throws IOException,
                       AutomationException

Label at the specified index.

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Parameters:

index - The index (in)

Returns:

The label

Throws:

IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.

setLabel

void setLabel(int index,
              String label)
              throws IOException,
                     AutomationException

Label at the specified index.

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Parameters:

index - The index (in)

label - The label (in)

Throws:

IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.

getDescription

String getDescription(int index)
                      throws IOException,
                             AutomationException

Description at the specified index.

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Parameters:

index - The index (in)

Returns:

The text

Throws:

IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.

setDescription

void setDescription(int index,
                    String text)
                    throws IOException,
                           AutomationException

Description at the specified index.

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Parameters:

index - The index (in)

text - The text (in)

Throws:

IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.

getBreak

double getBreak(int index)
                throws IOException,
                       AutomationException

Break value at the specified index. Break(0) is the lowest break and represents the upper bound of the lowest class.

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Parameters:

index - The index (in)

Returns:

The value

Throws:

IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.

setBreak

void setBreak(int index,
              double value)
              throws IOException,
                     AutomationException

Break value at the specified index. Break(0) is the lowest break and represents the upper bound of the lowest class.

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Parameters:

index - The index (in)

value - The value (in)

Throws:

IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.

getMinimumBreak

double getMinimumBreak()
                       throws IOException,
                              AutomationException

Minimum break, i.e. the lower bound of the first class.

Remarks

Represents the minimum value symbolized by the renderer. Values less than the MinimumBreak will not be drawn by the renderer, thererfore is is common to set this property to the minimum value in the dataset being symbolized.

If you change the data being symbolized, you may need to reset the MinimumBreak if the minimum value in the data is affected.

MinimumBreak does NOT equal Break(0). Break(0) is the highest value in the first class, while MinimumBreak is functionally the lowest value in the first class.

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Supported Platforms

Windows, Solaris, Linux

Returns:

The value

Throws:

IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.

setMinimumBreak

void setMinimumBreak(double value)
                     throws IOException,
                            AutomationException

Minimum break, i.e. the lower bound of the first class.

Remarks

Commonly the minimum value in the dataset. Does NOT equal Break(0).

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Supported Platforms

Windows, Solaris, Linux

Parameters:

value - The value (in)

Throws:

IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.

isSortClassesAscending

boolean isSortClassesAscending()
                               throws IOException,
                                      AutomationException

Indicates if classes are displayed in increasing order in legends/TOC.

Description

Indicates whether or not the classes are sorted by their values in ascending order.

Remarks

Changing this property reverses the Break array, but keeps the Symbol, Label, and Description arrays intact and in the same order.

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Supported Platforms

Windows, Solaris, Linux

Returns:

The ascending

Throws:

IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.

setSortClassesAscending

void setSortClassesAscending(boolean ascending)
                             throws IOException,
                                    AutomationException

Indicates if classes are displayed in increasing order in legends/TOC.

Description

SortClassesAscending is whether the classes are sorted by their values in ascending order.

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Supported Platforms

Windows, Solaris, Linux

Parameters:

ascending - The ascending (in)

Throws:

IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.

getBackgroundSymbol

IFillSymbol getBackgroundSymbol()
                                throws IOException,
                                       AutomationException

Background fill symbol used when graduated marker symbols are draw on polygon features.

Description

BackgroundSymbol is the fill symbol that is used when the layer's features are polygons and the ClassBreaksRenderer is used to draw graduated marker symbols.

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Supported Platforms

Windows, Solaris, Linux

Returns:

A reference to a com.esri.arcgis.display.IFillSymbol

Throws:

IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.

setBackgroundSymbol

void setBackgroundSymbol(IFillSymbol sym)
                         throws IOException,
                                AutomationException

Background fill symbol used when graduated marker symbols are draw on polygon features.

Description

BackgroundSymbol is the Symbol that is used when the layer's features are polygons and the classification is applied to a graduated symbol.

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Supported Platforms

Windows, Solaris, Linux

Parameters:

sym - A reference to a com.esri.arcgis.display.IFillSymbol (in)

Throws:

IOException - If there are interop problems.

AutomationException - If the ArcObject component throws an exception.