mqr.spc.

ShewhartParams

class mqr.spc.ShewhartParams

Base class of Shewhart-type control methods.

Other types should implement at least these functions to be monitored with SPC rules expressed in terms of “sigma”s, or standard deviations of the sampling distribution used by the control method.

Methods

asdict()	Returns a dict representation of this class.
lcl(nobs)	Calculates the lower control limits for samples with sizes in nobs.
se(nobs)	Calculates the standard error of samples with sizes nobs.
statistic(samples)	Calculates the control statistic from samples.
target()	Process target value for this monitoring method.
ucl(nobs)	Calculates the upper control limits for samples with sizes in nobs.