| Type: | Package |
| Title: | Generalized Process Capability Indices under Progressive Type-II Censoring |
| Version: | 0.1.0 |
| Description: | Provides a comprehensive generalized framework for parameter estimation and Generalized Process Capability Indices (GPCIs) under Progressive Type-II censored data using the MleCensoR package. Accepts user-supplied probability density functions (PDF/PMF), cumulative distribution functions (CDF), and survival functions (SF). Computes classical and generalized capability indices including Cpy (Maiti et al., 2010 <doi:10.1080/16843703.2010.11673233>), Spmk (Dey & Saha, 2019 <doi:10.1007/s41872-019-00081-4>), CpTk (Saha et al., 2019), Cpc (Saha et al., 2022 <doi:10.1080/02664763.2021.1971632>), CNpmc (Alotaibi et al., 2022 <doi:10.1155/2022/3135264>), CNpmkc (Saha et al., 2024 <doi:10.1142/S021853932450013X>), CNpk (Saha et al., 2018 <doi:10.1080/21681015.2018.1437793>), and Vannman's Cp(u,v) family. Evaluates parametric and non-parametric bootstrap confidence intervals at 90%, 95%, and 99% levels of significance. Computes Standard Errors, Mean Squared Error (MSE), Bias, and Coverage Probabilities for model parameters and capability indices. References: Balakrishnan & Aggarwala (2000) <doi:10.1007/978-1-4612-1186-0>, Maiti, Saha & Nanda (2010) <doi:10.1080/16843703.2010.11673233>, Saha, Dey & Maiti (2018) <doi:10.1080/21681015.2018.1437793>, Dey & Saha (2019) <doi:10.1007/s41872-019-00081-4>, Saha, Dey & Maiti (2019), Alotaibi, Dey & Saha (2022) <doi:10.1155/2022/3135264>, Saha, Dey & Nadarajah (2022) <doi:10.1080/02664763.2021.1971632>, Saha, Tripathi & Dey (2024) <doi:10.1142/S021853932450013X>. |
| License: | MIT + file LICENSE |
| Encoding: | UTF-8 |
| RoxygenNote: | 7.3.3 |
| Depends: | R (≥ 4.0.0) |
| Imports: | stats, graphics, grDevices, numDeriv, boot, MleCensoR |
| Suggests: | testthat (≥ 3.0.0), knitr, rmarkdown |
| VignetteBuilder: | knitr |
| Config/testthat/edition: | 3 |
| NeedsCompilation: | no |
| Packaged: | 2026-07-31 00:05:22 UTC; shikhar tyagi |
| Author: | Shikhar Tyagi |
| Maintainer: | Shikhar Tyagi <shikhar1093tyagi@gmail.com> |
| Repository: | CRAN |
| Date/Publication: | 2026-08-07 19:20:02 UTC |
gpciProgTyII: Generalized Process Capability Indices under Progressive Type-II Censoring
Description
Provides a comprehensive generalized framework for parameter estimation and Generalized Process Capability Indices (GPCIs) under Progressive Type-II censored data using the MleCensoR package. Supports user-supplied probability density functions (PDF/PMF), cumulative distribution functions (CDF), and survival functions (SF). Computes classical and generalized capability indices including Cpy, Spmk, CpTk, Cpc, CNpmc, CNpmkc, CNpk, and Vannman's Cp(u,v) family. Evaluates parametric and non-parametric bootstrap confidence intervals at 90%, 95%, and 99% levels of significance. Computes Standard Errors, Mean Squared Error (MSE), Bias, and Coverage Probabilities for model parameters and capability indices.
Author(s)
Maintainer: Shikhar Tyagi shikhar1093tyagi@gmail.com (ORCID)
Authors:
Sumit Kumar stats.sumitbhal@gmail.com
Arvind Pandey arvindmzu@gmail.com
Bhupendra Singh bhupendra.rana@gmail.com
Vrijesh Tripathi vrijesh.tripathi@uwi.edu
Bootstrap Confidence Intervals and Performance Evaluation for Progressive Type-II GPCI
Description
Computes parametric and non-parametric bootstrap confidence intervals for Generalized Process Capability Indices (GPCIs) and model parameters under progressive Type-II censoring at 90%, 95%, and 99% significance levels.
Usage
boot_ci_prog(
fit,
B = 1000,
alpha = c(0.1, 0.05, 0.01),
method = c("percentile", "normal", "basic", "BCp", "BCa", "studentized"),
type = c("parametric", "nonparametric")
)
gpc_boot(
fit,
B = 1000,
alpha = c(0.1, 0.05, 0.01),
method = c("percentile", "normal", "basic", "BCp", "BCa", "studentized"),
type = c("parametric", "nonparametric")
)
Arguments
fit |
A |
B |
Number of bootstrap replicates (default 1000). |
alpha |
Vector of significance levels (default |
method |
Confidence interval method. Options: |
type |
Resampling type: |
Value
An object of class "gpc_prog_ci" containing confidence interval tables, standard errors, MSE, and bias.
Examples
dist_exp <- dist_weibull(shape = 1, scale = 1)
x <- c(0.5, 1.2, 2.1, 3.4, 4.8)
r <- c(1, 0, 2, 0, 1)
fit <- capability_prog(x = x, r_removals = r, distribution = dist_exp, USL = 6, LSL = 0)
ci <- boot_ci_prog(fit, B = 50, alpha = c(0.10, 0.05, 0.01), method = "percentile")
print(ci)
Compute Generalized Process Capability Indices for Progressive Type-II Censored Data
Description
Computes classical and generalized Process Capability Indices (PCIs) for progressive
Type-II censored data using model parameter estimates obtained from MleCensoR.
Usage
capability_prog(
x = NULL,
r_removals = NULL,
distribution,
USL,
LSL,
target = (USL + LSL)/2,
indices = c("Cpy", "Cp", "Cpk", "Cpu", "Cpl", "Cpm", "Cpmk", "Spmk", "CpTk", "Cpc",
"CNpmc"),
u = 1,
v = 1,
mode = c("moments", "quantile"),
fit = TRUE,
C0 = 1,
C1 = 0,
C2 = 1,
tolerance_t = USL - LSL,
P0 = 0.9973002,
LDL = LSL,
UDL = USL
)
gpc_fit(
x = NULL,
r_removals = NULL,
distribution,
USL,
LSL,
target = (USL + LSL)/2,
indices = c("Cpy", "Cp", "Cpk", "Cpu", "Cpl", "Cpm", "Cpmk", "Spmk", "CpTk", "Cpc",
"CNpmc"),
u = 1,
v = 1,
mode = c("moments", "quantile"),
fit = TRUE,
C0 = 1,
C1 = 0,
C2 = 1,
tolerance_t = USL - LSL,
P0 = 0.9973002,
LDL = LSL,
UDL = USL
)
Arguments
x |
Numeric vector of observed failure times under progressive Type-II censoring. Can be |
r_removals |
Numeric vector of removal counts (censoring scheme R). |
distribution |
A |
USL |
Upper Specification Limit. |
LSL |
Lower Specification Limit. |
target |
Process target (defaults to |
indices |
Vector of capability indices to compute. Choices include |
u |
Weight parameter |
v |
Weight parameter |
mode |
Mode of evaluation: |
fit |
Logical. If |
C0, C1, C2 |
Parameters for loss/tolerance cost function in |
tolerance_t |
Tolerance length |
P0 |
Desired conformance level for |
LDL, UDL |
Lower and Upper Desired Limits for |
Value
An object of class c("gpc_prog_fit", "gpcifit").
Examples
dist_exp <- dist_weibull(shape = 1, scale = 1)
x <- c(0.5, 1.2, 2.1, 3.4, 4.8)
r <- c(1, 0, 2, 0, 1)
cap <- capability_prog(x = x, r_removals = r, distribution = dist_exp, USL = 6, LSL = 0)
print(cap)
Monte Carlo Simulation and Coverage Probability Evaluation
Description
Evaluates standard error, MSE, bias, and empirical coverage probability for parameters and GPCIs under progressive Type-II censoring.
Usage
eval_performance(
distribution,
r_removals,
USL,
LSL,
target = (USL + LSL)/2,
true_indices = NULL,
M = 100,
B = 200,
alpha = c(0.1, 0.05, 0.01)
)
gpc_sim(
distribution,
r_removals,
USL,
LSL,
target = (USL + LSL)/2,
true_indices = NULL,
M = 100,
B = 200,
alpha = c(0.1, 0.05, 0.01)
)
Arguments
distribution |
A |
r_removals |
Progressive censoring scheme vector R. |
USL |
Upper Specification Limit. |
LSL |
Lower Specification Limit. |
target |
Process target. |
true_indices |
Optional named vector of true index values. |
M |
Number of Monte Carlo simulation runs (default 100). |
B |
Number of bootstrap iterations per run (default 200). |
alpha |
Vector of significance levels (default |
Value
A list containing performance tables and coverage probabilities.
Examples
dist_true <- dist_weibull(shape = 2, scale = 5)
r_scheme <- c(2, 0, 3, 0, 1)
eval_res <- eval_performance(dist_true, r_scheme, USL = 10, LSL = 0, M = 5, B = 20)
print(eval_res)
Parameter Estimation for Progressive Type-II Censored Data using MleCensoR
Description
Fits process distribution parameters to progressive Type-II censored data using
the MleCensoR package (mle_progressive_type2).
Usage
fit_prog_ty2(
x,
r_removals,
distribution,
start = NULL,
method = NULL,
lower = NULL,
upper = NULL,
...
)
Arguments
x |
Numeric vector of observed failure times (must be sorted in ascending order). |
r_removals |
Numeric vector of progressive removal counts (censoring scheme R). |
distribution |
A |
start |
Vector of initial parameter values. |
method |
Optimization method (e.g. |
lower |
Optional lower bounds for parameters. |
upper |
Optional upper bounds for parameters. |
... |
Additional arguments passed to |
Value
A fitted gpc_dist object with updated parameters, log-likelihood, standard errors, and covariance matrix.
Examples
dist_exp <- dist_weibull(shape = 1, scale = 1)
x <- c(0.5, 1.2, 2.1, 3.4, 4.8)
r <- c(1, 0, 2, 0, 1)
fit <- fit_prog_ty2(x = x, r_removals = r, distribution = dist_exp)
Dispatcher for Index Value Retrieval
Description
Dispatcher for Index Value Retrieval
Usage
gpc_index(fit, index)
Arguments
fit |
A |
index |
Name of index to extract or compute. |
Value
Numeric value of the specified index.
Examples
dist_exp <- dist_weibull(shape = 1, scale = 1)
x <- c(0.5, 1.2, 2.1, 3.4, 4.8)
r <- c(1, 0, 2, 0, 1)
fit <- capability_prog(x = x, r_removals = r, distribution = dist_exp, USL = 6, LSL = 0)
gpc_index(fit, "Cpy")
Custom Distribution Object Builder for Progressive Type-II GPCI
Description
Builds a distribution specification object for parameter estimation and Generalized Process Capability Indices (GPCIs) under Progressive Type-II Censored Data.
Usage
make_gpc_dist(
name,
pdf,
cdf,
surv = NULL,
quantile = NULL,
start,
param_names = paste0("param", seq_along(start)),
support = c(0, Inf)
)
Arguments
name |
Character string giving the name of the distribution. |
pdf |
Function |
cdf |
Function |
surv |
Function |
quantile |
Optional function |
start |
Vector of initial parameter values for estimation. |
param_names |
Character vector of parameter names. |
support |
Numeric vector of length 2 giving domain support of the distribution. |
Value
An object of class "gpc_dist".
Examples
pdf_exp <- function(x, theta) dexp(x, rate = theta[1])
cdf_exp <- function(x, theta) pexp(x, rate = theta[1])
surv_exp <- function(x, theta) 1 - pexp(x, rate = theta[1])
dist <- make_gpc_dist("Exponential", pdf_exp, cdf_exp, surv_exp, start = c(1), param_names = "rate")
Visualization Functions for Progressive Type-II GPCI
Description
Provides plot S3 methods for fitted progressive Type-II capability objects and bootstrap confidence interval results.
Usage
## S3 method for class 'gpc_prog_fit'
plot(x, ...)
## S3 method for class 'gpc_prog_ci'
plot(x, index = NULL, ...)
Arguments
x |
Object of class |
... |
Additional plot parameters. |
index |
Name of index or parameter to plot for |
Value
Invisibly returns the input object.
Examples
dist_exp <- dist_weibull(shape = 1, scale = 1)
x <- c(0.5, 1.2, 2.1, 3.4, 4.8)
r <- c(1, 0, 2, 0, 1)
fit <- capability_prog(x = x, r_removals = r, distribution = dist_exp, USL = 6, LSL = 0)
plot(fit)
Predefined Distribution Specifications
Description
Built-in helper functions creating "gpc_dist" objects for standard process distributions.
Usage
dist_normal(mean = 0, sd = 1)
dist_weibull(shape = 1, scale = 1)
dist_gamma(shape = 1, rate = 1)
dist_exp_exp(alpha = 1, lambda = 1)
dist_logistic_exp(alpha = 1, lambda = 1)
Arguments
mean |
Initial mean for Normal distribution. |
sd |
Initial standard deviation for Normal distribution. |
shape |
Initial shape parameter. |
scale |
Initial scale parameter. |
rate |
Initial rate parameter. |
alpha |
Initial alpha shape parameter. |
lambda |
Initial lambda scale parameter. |
Value
A "gpc_dist" object.
Examples
d_norm <- dist_normal()
d_weib <- dist_weibull()