altopt.ic {ALTopt}

Optimal design with interval censoring.

Description

altopt.ic creates D, U or I optimal design of the accelerated life testing with interval censoring plan.

Usage

altopt.ic(
  optType,
  N,
  t,
  k,
  nf,
  alpha,
  formula,
  coef,
  useCond,
  useLower,
  useUpper,
  nOpt = 1,
  nKM = 30,
  nCls = NULL
)

Arguments

optType

the choice of "D", "U" and "I" optimality.

N

the number of test units.

t

the total testing time.

k

the number of time intervals.

nf

the number of stress factors.

alpha

the value of the shape parameter of Weibull distribution.

formula

the object of class formula which is the linear predictor model.

coef

the numeric vector containing the coefficients of each term in formula.

useCond

the numeric vector of use condition. It should be provided when optType is "U". The length of the vector should be same as the number of stress factors.

useLower

the numeric vector of lower bound of use region. It should be provided when optType is "I". The length of the vector should be same as the number of stress factors.

useUpper

the numeric vector of upper bound of use region. It should be provided when optType is "I". The length of the vector should be same as the number of stress factors.

nOpt

the number of repetition of optimization process. Default is 1.

nKM

the number of repetition of k-means clustering. Default is 20.

nCls

the number of clusters used for k-means clustering. If not specified, it is set as the number of parameters in the linear predictor model.

Value

A list with components

• call: the matched call.

• opt.design.ori: the original optimal design.

• opt.value.ori: the objective function value of opt.design.ori.

• opt.design.rounded: the optimal design clustered by rounding in third decimal points.

• opt.value.rounded: the objective function value of opt.design.rounded.

• opt.design.kmeans: the optimal design clustered by kmeans.

• opt.value.kmeans: the objective function value of opt.design.kmeans.

References

Monroe, E. M., Pan, R., Anderson-Cook, C. M., Montgomery, D. C. and Borror C. M. (2011) A Generalized Linear Model Approach to Designing Accelerated Life Test Experiments, Quality and Reliability Engineering International 27(4), 595–607

Yang, T., Pan, R. (2013) A Novel Approach to Optimal Accelerated Life Test Planning With Interval Censoring, Reliability, IEEE Transactions on 62(2), 527–536

See Also

kmeans, alteval.ic

Examples

## Not run: 
# Generating D optimal design for interval censoring.
altopt.ic("D", 100, 30, 5, 2, 1, formula = ~ x1 + x2 + x1:x2,
coef = c(0, -4.086, -1.476, 0.01))

# Generating U optimal design for interval censoring.
altopt.ic("D", 100, 30, 5, 2, 1, formula = ~ x1 + x2 + x1:x2,
coef = c(0, -4.086, -1.476, 0.01), useCond = c(1.758, 3.159))

# Generating I optimal design for interval censoring.
altopt.ic("D", 100, 30, 5, 2, 1, formula = ~ x1 + x2 + x1:x2,
coef = c(0, -4.086, -1.476, 0.01), useLower = c(1.458, 2.859),
useUpper = c(2.058, 3.459))

## End(Not run)