The Color Classes dialog is
opened when you click the Color Classes
button on the Map page
of the Property Manager. The color
classes operate similarly to hatch map coloring.
Set the Color method to Classes to activate the Classes
button. You can categorize
the data by color, and these colors are plotted on the area prisms. The
variable used to color the prisms can be different from the variable used
for prism height (General page).
Set data classes and fill properties in the Color Classes dialog.
Data
Select the data for prism colors in the Data column for class list. The list shows the available data columns from the linked data sheet. This variable can be different from the prism height variable, so you can show two variables at one time on the map.
Undefined Data
Color for all other data is the color used for all areas without a corresponding data value and for areas that contain values that do not fall in the specified classes.
Data Classes
Number of classes specifies the number of color classes (groupings) used for the variable. Up to 100 classes can be specified.
Saving and Loading Classes
Once the classes are defined, they can be saved for reuse in a class file [.CLS]. Click the Save Classes button to save the classes. To use an existing class file, click the Load Classes button. You can also save the class information to a data file by clicking the Save Class Info to Worksheet File button.
Classification Method
The Classification method is the method by which the class limits are calculated.
Equal Number calculates the class minimum and maximums such that an approximately equal number of data values fall within each class.
Equal Intervals calculates the class limits so that the interval between the minimum value and maximum value of each class is equal. The Increment box is displayed when Equal Intervals is selected, and this shows the range covered by each class.
User Defined allows you to create your own class definitions. Overlapping or discontinuous classes are not allowed. Double-click on the minimum and maximum values in the class list to define the classes after you define the Number of classes.
Standard deviation generates data classes based on the standard deviation of the data. When the Standard deviation method is selected, the Increment field appears. The Increment field allows you to define the standard deviation increment to establish the class ranges and number of classes. The Increment and Number of classes values are dependent upon each other, so changing one value automatically changes the other.
The Jenks' Natural breaks method creates classes based on the optimal natural breaks in your data.
Class Information
The Objects in classes group displays summary statistics and allows you to specify the properties for each class.
>=Minimum and <Maximum indicate the lower and upper limits for the class. If a data value is greater than or equal to the minimum value and less than the maximum value, it is plotted in the class. You can change these values by double-clicking on a minimum or maximum value to change it in the Class Limit dialog.
The % column indicates the percentage of linked data in the particular class. This value cannot be edited and is for informational purposes only.
The Count column indicates the number of data included in each class. This value cannot be edited and is for informational purposes only.
The Color column specifies the class's color. To change the color for a particular class, double-click the color in the list, and select a new color in the Colors dialog. To change the entire color spectrum, click the word Color at the top of the column and select a new color spectrum from the Color Spectrum dialog. Click the Custom... button in the Color Spectrum dialog to create a custom spectrum in the Colormap dialog.
The Name column indicates the optional class title used in the legend.
Statistics
The Data Statistics box shows data statistics for the selected variable.
Data Limits
The Set Data limits group lets you specify the extents of the prism classes. If you would like to keep the prism class range the same for a series of maps, even if your data range varies between data sets, check the User defined box and set the Min and Max values. The minimum value is plotted as the minimum value of the first class and the maximum value is plotted as the maximum value of the last class. This is useful when you would like to plot a series of maps and show the same colors at the same classes each time. Use Map | Legend to display a legend of the prism map class colors and values.
See Also