qcc (version 2.3)

stats.c: Functions to plot Shewhart c chart

Description

Statistics used in computing and drawing a Shewhart c chart.

Usage

stats.c(data, sizes)
sd.c(data, sizes, ...)
limits.c(center, std.dev, sizes, conf)

Arguments

data

the observed data values

center

sample/group center statistic.

sizes

samples sizes.

std.dev

within group standard deviation.

conf

a numeric value used to compute control limits, specifying the number of standard deviations (if conf > 1) or the confidence level (if 0 < conf < 1).

...

further arguments are ignored.

Value

• The function stats.c returns a list with components statistics and center.

  The function sd.c returns std.dev the standard deviation of the statistic charted.

  The function limits.c returns a matrix with lower and upper control limits.

References

Montgomery, D.C. (2005) Introduction to Statistical Quality Control, 5th ed. New York: John Wiley & Sons. Wetherill, G.B. and Brown, D.W. (1991) Statistical Process Control. New York: Chapman & Hall.

See Also

qcc