Description Usage Arguments Details Value References See Also Examples
View source: R/attrCUSUM_getxxx_and_utils.R
Computation of suitable control limits for attribute FSI-CUSUM control chart for mean increase based on specified reference value and in-control ANSS/ARL.
1 2 | getContl(anss.target = 370.4, refv, c.zero = 0, process, maxndec = 7L,
maxnumsubI = 6000L)
|
anss.target |
A predetermined in-control ANSS/ARL (≤50000L), default is 370.4. |
refv |
A reference value of CUSUM statistic. |
c.zero |
An initial state of CUSUM statistic (default is 0). |
process |
An object of function standing for pmf of count process of interest. See 'Details'. |
maxndec |
The maximum number of decimal places
of |
maxnumsubI |
The maximum number of sub-intervals in [100,6000] to be used in applying the Markov chain approach. |
For CUSUM control chart for detecting mean increase, the CUSUM statistic (C_{t}) are defined as following:
C_{t}=max(C_{t-1}, 0) + X_{t} - k, t=1,2,...,
wherein X_{t} is a count process of interest, k is the reference value and C_{0} is the initial state.
The argument process
is an object of function such that
for given integer-valued vector x
,
process(x)
returns P(X=x)
where X is a random variable of interest.
If the number of sub-intervals
for transient states of Markov chain is greater than maxnsubI
,
it will be set to be a suitable value
being less than or equal maxnsubI
.
Invalid arguments rise an error with a helpful message.
This function currently provides only the case for monitoring of mean increase. We leave other issues as our future work.
A list including followings:
refv.act |
A reference value of CUSUM statistic used actually for computation. |
c.zero.act |
An initial state of CUSUM statistic used actually for computation. |
sol1,sol2 |
Vector of control limits and corresponding ANSS/ARLs |
Reynolds et al. (1990). CUSUM Charts with Variable Sampling Intervals, Technometrics, 32(4), 371-384.
1 2 3 |
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