Weibull Probability Paper - Variables (Optional) Tab

Select the Variables (optional) tab of the Weibull Probability Paper dialog box to access the options described here.

Variables for the plot (optional)

Use the options in the Variables for the plot (optional) group box to specify variables for the probability plot.

Variables (failure times & censoring indicator)

Click the Variables (failure times & censoring indicator) button to display the standard variable selection dialog, in which you select failure times and censoring indicator variables to be used for the probability plot.

Code for complete responses (failures)

Use the Codes for complete responses (failures) box to specify the codes or text labels that were used in the censoring indicator variable to uniquely identify complete (uncensored) observations. To review all codes in the respective variable, double-click on the respective edit field (or press the F2 key on your keyboard) to display the Variable dialog. The first two valid values found in the censoring indicator variable are taken as the default codes for uncensored (complete) and censored data, respectively. Note that this box is only available if a censoring indicator variable was selected.

Code for censored responses

Specify the codes or text labels that were used in the censoring indicator variable to uniquely identify incomplete (censored) observations. To review all codes in the respective variable, double-click on the respective edit field (or press the F2 key on your keyboard) to display the Variable dialog. Note that this option is only available if a censoring indicator variable was selected.

Add constant to 0 times

The Weibull distribution is bounded on the left side, i.e., all values must be greater than the respective location parameter (greater than 0, by default). When the Add constant to 0 times check box is selected, Statistica replaces zero failure times with the constant specified in the adjacent box, before fitting or plotting the Weibull distribution. When the check box is cleared, cases with zero failure times will be excluded from the analysis (treated as missing data).