Provides access to members that control a renderer which is used to draw graduated color (choropleth) and graduated symbol maps.
Product Availability
Description
IClassBreaksRenderer defines the parameters for drawing
features based on the values of a quantitative attribute that
is statistically grouped by a classification
algorithm.
When To Use
Use this interface to make changes to the drawing properties of a ClassBreaksRenderer.
Members
| Description | ||
|---|---|---|
 |
BackgroundSymbol | Background fill symbol used when graduated marker symbols are draw on polygon features. |
|
Break | Break value at the specified index. Break(0) is the lowest break and represents the upper bound of the lowest class. |
|
BreakCount | Number of class breaks (equal to the number of classes). |
|
Description | Description at the specified index. |
|
Field | Classification field. |
|
Label | Label at the specified index. |
|
MinimumBreak | Minimum break, i.e. the lower bound of the first class. |
|
NormField | Normalization field. |
|
SortClassesAscending | Indicates if classes are displayed in increasing order in legends/TOC. |
|
Symbol | Symbol at the specified index (used to draw features in the specified class). |
CoClasses that implement IClassBreaksRenderer
| CoClasses and Classes | Description |
|---|---|
| ClassBreaksRenderer | A renderer that can be used to draw graduated color (choropleth) and graduated symbol maps. |
| NetworkTrafficRenderer | A renderer used to display network dataset traffic. |
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.
See Also
ClassBreaksRenderer Class | DefinedInterval Class | NaturalBreaks Class | StandardDeviation Class | Quantile Class | EqualInterval Class