Prediction Graph

Use the Prediction Graph tab to predict the Y variable for a specified Time value. Figure 7.16 shows the Prediction Plot tab.

Figure 7.16 Prediction Plot Tab

For the GaAs Laser example, no data was collected after 4000 hours. If you want to predict the percent increase in operating current after 5000 hours, enter 5000 and click Go. A plot is produced showing the estimated percent decrease after 5000 hours for all the units. See Figure 7.17.

Figure 7.17 Prediction Plot

The Prediction Plot red triangle menu has the following options:

Save Predictions

saves the predicted Y values to a data table. When one of the Longitudinal Prediction Interval options is enabled, the table also includes the intervals.

Longitudinal Prediction Interval

is used to show confidence or prediction intervals for the estimated Y on the Prediction Plot. When intervals are enabled, the intervals are also included in the data table that is created when using the Save Predictions option.

Longitudinal Prediction Time

is used to specify the time value for which you want to predict the Y.

Longitudinal Prediction Alpha

is used to specify the alpha level used for the intervals.