Quality Control Chart Object
DESCRIPTION:
Class of objects that results from computing group summary statistics, the within group standard deviation, and other information pertinent to producing Shewhart and cusum quality control charts. The class is "qcc".
GENERATION:
This class of objects is returned from qcc. In addition, shewhart creates objects of class c("shewhart", "qcc") inheriting from classes "qcc" and "shewhart", and cusum creates objects of class c("cusum", "shewhart", "qcc"), inheriting from "qcc", "shewhart", and "cusum".

An object of class "qcc" represents data from an in-control process necessary to produce a Shewhart or cusum quality control chart. Objects of class "shewhart" and "cusum" contain additional information pertinent to Shewhart and cusum control charts.

METHODS:
The class "qcc" has methods for the following generic function: print
INHERITANCE:
Class "shewhart" inherits from class "qcc" and class "cusum" inherits from classes "shewhart" and "qcc".
STRUCTURE:
The "qcc" object is implemented as a list with the following components:
statistics:
a vector of group summary statistics.
sizes:
a vector of group sample sizes.
center:
the center of statistics computed as specified by type.
std.dev:
an estimate of the overall within group standard deviation.
type:
a character string or function specifying group statistics to compute. If a character string, it must be one of "xbar", "s", "R", "p", "np", "u", or "c".
data.name:
a character string (vector of length 1) containing the name of the input data.
SEE ALSO:
qcc .