Defining Data: Variable Definition

Click the Add button in the Additional Variables dialog box to display the Variable Definition dialog box.

Short name

Enter a short name for the variable in this box.

Long name

Enter into this box, either a formula using the Spreadsheet Formula Syntax, or a more descriptive name for the variable. For example, consider a Data Configuration that contains measurements of thickness of a material, before and after a coat of paint. You can create an Additional Variable and express a formula, subtracting the "before" measurement from the "after" to derive the thickness of the coat of paint. The syntax dictates that you prefix the expression with and equals sign. (e.g. = PostPaint - PrePaint) When the Analysis Configuration is run and data (variables) appear in the resulting STATISTICA Spreadsheet, any new variables that you have defined here will appear last (far right of all other variables).

Perform quality control analyses on this variable

Select this check box if you want quality control analyses to be performed on this variable. When you select this check box, options for specifying the quality control analysis will be displayed.

Chart type

Select a quality control chart type from this drop-down list. Available chart types are Xbar & R, Individuals & Moving Range, Xbar & S, Moving Average, Moving Average and R, Moving Average and S, EWMA and R, and EWMA and S. Additional options for specifying sample sizes and parameters are displayed based on the type of chart selected here.

Sample size

For all chart types above except the Individuals & Moving Range chart, you can specify the sample size by typing the number in the box or by adjusting the number with the microscrolls.

Minimum n per sample

Specify a minimum n per sample by typing it in or by adjusting the number with the microscrolls. Samples with fewer observations than the minimum specified will be ignored. This option is available for Xbar & R, Xbar & S, Moving Average, EWMA and R, and EWMA and S chart types.

Moving average span

Specify here the span for the n-point moving average line, for the moving average (MA) chart that is generated when Moving Average, Moving Average & R, or Moving Average & S is selected in the Chart type list.

EWMA lambda

Specify here the value of lambda for constructing the exponentially weighted moving average line (chart). See also, computational details for more information.

Static specs

Click this button to display the IQC Specifications (static) dialog. Use this dialog to establish static specs to that will be used in the calculations necessary for control charting and process capability analysis.