ALTopt-package {ALTopt} | R Documentation |

Creates the optimal (D, U and I) designs for the accelerated life testing with right censoring or interval censoring. It uses generalized linear model (GLM) approach to derive the asymptotic variance-covariance matrix of regression coefficients. The failure time distribution is assumed to follow Weibull distribution with a known shape parameter and log-linear link functions are used to model the relationship between failure time parameters and stress variables. The acceleration model may have multiple stress factors, although most ALTs involve only two or less stress factors. ALTopt package also provides several plotting functions including contour plot, Fraction of Use Space (FUS) plot and Variance Dispersion graphs of Use Space (VDUS) plot. For more details, see Seo and Pan (2015) <doi:10.32614/RJ-2015-029>.

Package: | ALTopt |

Version: | 0.1.2 |

Authors@R: | as.person(c( "Kangwon Seo <seoka@missouri.edu> [aut, cre]", "Rong Pan <rong.pan@asu.edu> [aut]" )) |

Depends: | R (>= 3.0.0) |

License: | GPL-3 |

LazyData: | true |

Imports: | cubature (>= 1.0), lattice (>= 0.20), methods |

Built: | R 3.6.1; ; 2019-12-12 12:30:00 UTC; windows |

Index:

alteval.ic Design evaluation with interval censoring. alteval.rc Design evaluation with right censoring. altopt.ic Optimal design with interval censoring. altopt.rc Optimal design with right censoring. compare.fus Comparing designs using FUS compare.vdus Comparing designs using VDUS convert.stress.level Coding and decoding stress level design.plot Design plot. pv.contour.ic Contour plot of prediction variance for a design with interval censoring. pv.contour.rc Contour plot of prediction variance for a design with right censoring. pv.fus.ic FUS (Fraction of Use Space) plot for interval censoring. pv.fus.rc FUS (Fraction of Use Space) plot for right censoring. pv.vdus.ic VDUS (Variance Dispersion of Use Space) plot for interval censoring. pv.vdus.rc VDUS (Variance Dispersion of Use Space) plot for right censoring.

Kangwon Seo [aut, cre], Rong Pan [aut]

Maintainer: Kangwon Seo <seoka@missouri.edu>

Seo, K. and Pan, R. (2015) ALTopt: An R Package for Optimal Experimental Design of Accelerated Life Testing. *The R Journal*, **7(2)**, 177-188.

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

```
altopt.rc, altopt.ic, alteval.rc, alteval.ic, pv.contour.rc, pv.contour.ic, pv.fus.rc, pv.fus.ic, pv.vdus.rc, pv.vdus.ic, compare.fus, compare.vdus,
design.plot, convert.stress.level
```

# D optimal design of two stress factors with right censoring. Design.D <- altopt.rc("D", 100, 100, 2, 1, formula = ~ x1 + x2 + x1:x2, coef = c(0, -4.086, -1.476, 0.01)) design.plot(Design.D$opt.design.rounded, x1, x2) pv.contour.rc(Design.D$opt.design.rounded, x1, x2, 100, 2, 1, formula = ~ x1 + x2 + x1:x2, coef = c(0, -4.086, -1.476, 0.01), useCond = c(1.758, 3.159)) FUS.D <- pv.fus.rc(Design.D$opt.design.rounded, 100, 2, 1, formula = ~ x1 + x2 + x1:x2, coef = c(0, -4.086, -1.476, 0.01), useLower = c(1.458, 2.859), useUpper = c(2.058, 3.459)) # U optimal design of two stress factors with right censoring. Design.U <- altopt.rc("U", 100, 100, 2, 1, formula = ~ x1 + x2 + x1:x2, coef = c(0, -4.086, -1.476, 0.01), useCond = c(1.758, 3.159)) design.plot(Design.U$opt.design.rounded, x1, x2) pv.contour.rc(Design.U$opt.design.rounded, x1, x2, 100, 2, 1, formula = ~ x1 + x2 + x1:x2, coef = c(0, -4.086, -1.476, 0.01), useCond = c(1.758, 3.159)) FUS.U <- pv.fus.rc(Design.U$opt.design.rounded, 100, 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)) # Comparing D and U optimal design. compare.fus(FUS.D, FUS.U)

[Package *ALTopt* version 0.1.2 Index]