Analysis Configuration: Calculated Variable

Click the Add button when the Calculated Variables options are displayed in the properties page to display these options.

Name

Define the name of the new Calculated Variable.

Formula

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 a Calculated 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 enabled.

Characteristic type

Select a characteristic type from this drop-down list. Variable contains numerical information, Attribute contains categorical information, and Aggregate Attribute contains categorical information that has been aggregated (counts averaged).

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, EWMA and S, C, U, Np, P, and Pareto. Additional options for specifying sample sizes and parameters are displayed based on the type of chart selected here.

Sample size

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

Minimum n per sample

Specify a minimum n per sample by typing it in this box. 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, EWMA and S, P, and Np 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).