NpChart is an np-chart for monitoring the number of defects when defects are not rare.

Namespace: Imsl.Chart2D.QC
Assembly: ImslCS (in ImslCS.dll) Version: 6.5.0.0

Syntax

C#
[SerializableAttribute]
public class NpChart : ShewhartControlChart
Visual Basic (Declaration)
<SerializableAttribute> _
Public Class NpChart _
	Inherits ShewhartControlChart
Visual C++
[SerializableAttribute]
public ref class NpChart : public ShewhartControlChart

Remarks

Control limits are computed using the binomial distribution. If defects are rare CChart should be used instead.

The control limits are at

np + k \sqrt{np(1-p)}
where p is the is the proportion of defective items, n is the sample size, 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{c}. Additional control limits can be added. The method AddWeco adds control limits with k = -2, -1, 1, 2.

The lower control limit is forced to have a minimum value of zero. The y-axis labels are formatted as integers.

Inheritance Hierarchy

See Also