XmR Class

XmR is an XmR chart for monitoring a process using moving ranges.

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

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

public class XmR : 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 moving range control chart uses the moving range of two successive observations to measure the process variability. This control chart is used for individual measurements (sample size = 1).

The moving range is defined to be $\mathrm{MR}_i=|x_i-x_{i-1}|$ .

The control limits are at

$\bar{x}+k\frac{\overline{MR}}{d_{2,2}}$

where $\bar{x}$ is the mean of all of the individual observations, $\overline{MR}$ is the mean of the moving averages, and k is the value of the "ControlLimit" attribute for the line. Additionally, $d_{2,n}=E(R)/\sigma$ where R is the range of a Gaussian distribution. Therefore $\overline{MR}/d_{2,2}$ is an estimate of the standard deviation.

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 $\bar{x}$ . Additionally 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)

XmR Class

Thread Safety

Remarks

Requirements

See Also