Classify column or Column slicing

Table window	Columns menu
Column Slicing

With Column Slicing, you can classify values in a column.

The upper boundary values of the classes and the class names can be specified in a group domain. A group domain can be created beforehand or during the Column Slicing process.

For example, to classify a column with percentage values ranging from 0 to 100 into 3 classes: Low (0-33%), Moderate (34-66%), High (67-100%), you can create a group domain which reads:

Upper Boundary	Group Name
33	Low
66	Moderate
100	High

Dialog box options:

Column name:

Select a value column which contains the values that you wish to classify.

Domain:

Select the name of a domain Group which was created beforehand, or create a new domain Group (click the little create button).

When you click the create button to create a new Group domain, the Create Domain dialog box will appear. After you specified a name for the domain Group and clicked the OK button, the domain Group editor will be opened.
Specify upper boundary values and names for the output groups via the Add Item to domain Group dialog box. Optionally, you can edit the colors of the output groups. When finished, you can close the editor.

Output column:

Type a name for the output column that will contain the classified values as groups.

When you click OK, the Column Properties dialog box will appear, stating the expression, the domain of the output column etc. You can accept all defaults.

After you clicked OK in the Column Properties dialog box, the new column with the classified values will appear in your table.

Tips:

When a group domain already exists, you can also directly type a classify expression on the command line of the table window:

OutputColumn = CLFY(ValueColumn, GroupDomain)

For more information, see Map and Table Calculation : CLFY function.

Example:

When a table contains a value column MyInputColumn and you created a domain group as above, the output column MyOutputColumn will read:

MyInputColumn	MyOutputColumn
15	Low
58	Moderate
66	Moderate
100	High
0	Low
75	High

Table window

Column Slicing