#### Editing Feature Variables

To edit one or more feature variable:

1. Select the Data Editor tab. If it is not available, select Tools | View Selection and mark the Editor check box.

2. Click on the Measurement Data tab.

3. Select the feature variables you want to edit by selecting a group of cells that corresponds to the variables.

4. Right-click, and select Edit variables... from the resulting short-cut menu.

6. The Variables box appears.

Variables dialog box

This dialog box lets you modify each selected feature variable's description, nominal value, tolerance values, and individual and subgroup control limits.

Feature Name - This lets you modify the name of the feature.

Variable Name - This lets you modify the variable name of the feature.

Description - This box lets you type a text description of the current feature variable. You can use the Description Report on the Text tab to view the descriptions given to each feature variable. See "Description Report".

Variable tolerance - This list contains the default tolerance values for the selected variable of variables as well as any custom tolerance definitions.

You can use the Add button to define any number of variable tolerance items. The defined items appear within the Variable tolerance list as well as in a list under the Change Tolerance toolbar icon in the Chart, Text, CAD, Custom Report, and Report tabs:

You can then select a pre-defined variable tolerance item from the list and apply it instead of the default. You can also select custom variables to a selected CNC item selected from the drop-down.

- Add - Select this option to define a new variable tolerance item to populate in the drop-down list.

- Rename - Select this option to rename a variable tolerance item in the list.

- Delete - Select this option to delete a variable tolerance item from the list.

Nominal - This box displays an editable nominal value (target value) for the feature variable.

Upper tolerance and Lower tolerance - These boxes determine the upper tolerance and lower tolerance for the feature variable. The upper and lower tolerances are both added to the nominal to produce the specification limits. The lower tolerance is generally expected to be negative, but this isn't required.

Distribution - This lets you select the distribution type for the variable. All variables are analyzed using a "normal distribution" by default. For data that doesn't use a normal distribution type, choose one of the other distribution models: Log Normal, Half Normal, Weibull, Rayleigh, or Exponential.

CNC - This drop-down provides a list of user-defined CNC machines that can be setup in DataPage+. To define a CNC and set the defined variable tolerances to, perform the following:

1. Select Tools | Options from the upper-right menu in DataPage+ as shown below.

2. The Options dialog is displayed - select the Definition tab.

3. Make the appropriate selection(s) from the drop-down list(s) as needed - click the OK button to save the change(s).

4. Access the Variables dialog as described above. The CNC drop-down list will be populated based on the selections made in the previous step as shown in the example below. Select each CNC machine from the CNC drop-down list and set the tolerances as needed. It is recommended to click the Save button after setting the tolerances for each CNC machine before moving on to set the tolerances for the next CNC machine.

5. Once all the CNC items in the drop-down list have been assigned the correct tolerance values and all changes have been saved, click on the Close button to complete the update(s).

Note: Ensure a CNC has been selected and tolerances have been assigned to each CNC from the drop-down list. Otherwise, since the first item in the list is empty, if selected, all CNC's will be tolerance-free.

Constant individual control limits - To avoid recalculating control limits when new data is entered, mark this check box. This overrides the upper and lower control limits for the X and R portions of Individual Charts. The x values are the control limits for the individual (upper) portion of the chart, and the R values are the control limits for their range (lower) portion of the chart. The range centerline control limit also can be overridden here.

Constant subgroup control limits - To avoid recalculating control limits when new data is entered, mark this check box. This overrides the upper and lower control portion for the X and R portions of subgroup chart. The X values are the control limits for the individual (upper) portions of the chart, and the R values are the control limits for the range (lower) portion of the chart. The range centerline control limit also can be overridden here.

Previous - This button lets you move to the previous record in a selection of multiple variables. If only one variable was selected this button will be disabled.

Next - This button lets you move to the next record in a selection of multiple variables. If only one variable was selected this button will be disabled.

To All - This is a button and a drop-down list. If only one variable was selected this button will be disabled.

- When you click the To All button portion, DataPage+ applies all the changes in the current record to all other records in the selection and closes the Variables dialog box.

- If you click the black drop down arrow, you can choose Changes Selection... a small Variables dialog box appears allowing you to choose a specific element whose value you want to update in all records in the selection.
  When you click OK, the dialog box closes and that specific value of the selected variables is updated.

OK - This applies your changes and closes the dialog box.

Cancel - This closes the dialog box without applying your changes.

Note: You can also use the Data Editor tab, Measurement Data tab to set the following values:
Nominal
Upper tolerance
Lower tolerance
Lower Control Limit (LCL)
Upper Control Limit (UCL)