UChart Class

UChart is a u-chart for monitoring the defect rate when defects are rare.

For a list of all members of this type, see UChart Members.

System.Object
   Imsl.Chart2D.AbstractChartNode
      Imsl.Chart2D.ChartNode
         Imsl.Chart2D.Data
            Imsl.Chart2D.QC.ShewhartControlChart
               Imsl.Chart2D.QC.UChart

public class UChart : ShewhartControlChart

Thread Safety

Public static (Shared in Visual Basic) members of this type are safe for multithreaded operations. Instance members are not guaranteed to be thread-safe.

Remarks

The defect rate is the number of defects found divided by the number of samples inspected. The number of defects are assumed to be rare. Control limits are computed using the Poisson distribution. If defects are not rare, use PChart instead. The sample sizes are not required to be equal.

The control limits are at

$\bar{u}+k\sqrt{\bar{u}/n}$

where $\bar{u}$ is the observed average number of defects per unit, n is the number of inspection units, and k is the value of the "ControlLimit" attribute for the line. By default, the chart contains an upper control limit line with k=3, a lower control limit line with k=-3, and a central line equal to $\bar{u}$ . Additional control limits can be added. The method AddWeco adds control limits with k = -2, -1, 1, 2.

Requirements

Namespace: Imsl.Chart2D.QC

Assembly: ImslCS (in ImslCS.dll)

UChart Class

Thread Safety

Remarks

Requirements

See Also