CControlLimits - Maple Help

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ProcessControl

 CControlLimits
 compute control limits for the C chart

 Calling Sequence CControlLimits(X, n, options)

Parameters

 X - data n - sample size options - (optional) equation(s) of the form option=value where option is one of confidencelevel or ubar; specify options for computing the control limits

Description

 • The CControlLimits command computes the upper and lower control limits for the C chart. Unless explicitly given, the standard deviation of the underlying quality characteristic is computed based on the data.
 • The first parameter X is a single data sample, given as a Vector or list. Each value represents the number of nonconformities in the corresponding sample.
 • The second parameter n specifies the size of the individual samples. All samples are expected to be of size n.

Computation

 • All computations involving data are performed in floating-point; therefore, all data provided must have type realcons and all returned solutions are floating-point, even if the problem is specified with exact values.
 • For more information about computation in the ProcessControl package, see the ProcessControl help page.

Options

 The options argument can contain one or more of the following options.
 • confidencelevel=realcons -- This option specifies the required confidence level. The default value is 0.9973, corresponding to a 3 sigma confidence level.
 • ubar=deduce or realcons -- This option specifies the average number of nonconformities per inspection unit.

Examples

 > $\mathrm{with}\left(\mathrm{ProcessControl}\right):$
 > $\mathrm{infolevel}\left[\mathrm{ProcessControl}\right]≔1:$
 > $A≔\left[12,8,6,9,10,12,11,16,10,6,20,15,9,8,6,8,10,7,5,8,5,8,10,6,9\right]$
 ${A}{≔}\left[{12}{,}{8}{,}{6}{,}{9}{,}{10}{,}{12}{,}{11}{,}{16}{,}{10}{,}{6}{,}{20}{,}{15}{,}{9}{,}{8}{,}{6}{,}{8}{,}{10}{,}{7}{,}{5}{,}{8}{,}{5}{,}{8}{,}{10}{,}{6}{,}{9}\right]$ (1)
 > $\mathrm{CControlLimits}\left(A,100\right)$
 $\left[{0.181764853697590}{,}{18.5382351463024}\right]$ (2)
 > $\mathrm{CControlLimits}\left(A,100,\mathrm{confidencelevel}=0.95\right)$
 $\left[{3.36366323844170}{,}{15.3563367615583}\right]$ (3)

References

 Montgomery, Douglas C. Introduction to Statistical Quality Control. 2nd ed. New York: John Wiley & Sons, 1991.

 See Also