Package: tptest
Type: Package
Title: Universal Turning Point and Inflection Point Tests
Version: 1.1.0
Date: 2026-09-30
Authors@R: c(
    person("Muhammad", "Alkhalaf", 
           email = "muhammedalkhalaf@gmail.com",
           role = c("aut", "cre", "cph"),
           comment = c(ORCID = "0009-0002-2677-9246")))
Description: Performs turning point and inflection point tests for
        U-shaped and inverse U-shaped relationships in regression
        models. Implements the Sasabuchi (1980) test as extended by
        Lind and Mehlum (2010) with support for quadratic, cubic,
        log-quadratic, and inverse functional forms. Features include
        delta-method standard errors, Fieller confidence intervals,
        Simonsohn (2018) two-lines test, and parametric bootstrap.
        Designed for post-estimation analysis of linear models, panel
        models, and quantile regression. References: Lind and Mehlum
        (2010) <doi:10.1111/j.1468-0084.2009.00569.x>; Sasabuchi
        (1980); Fieller (1954)
        <doi:10.1111/j.2517-6161.1954.tb00159.x>.
License: GPL-3
URL: https://github.com/muhammedalkhalaf/tptest
BugReports: https://github.com/muhammedalkhalaf/tptest/issues
Encoding: UTF-8
LazyData: true
Roxygen: list(markdown = TRUE)
RoxygenNote: 7.3.3
Depends: R (>= 4.0.0)
Imports: stats, graphics
Suggests: testthat (>= 3.0.0), knitr, rmarkdown, lmtest, sandwich, plm,
        quantreg
Repository: https://muhammedalkhalaf.r-universe.dev
Date/Publication: 2026-10-02 22:48:01 UTC
RemoteUrl: https://github.com/muhammedalkhalaf/tptest
RemoteRef: HEAD
RemoteSha: b6f0e6ab245dc018c67f4b7659b9269b63999409
NeedsCompilation: no
Packaged: 2026-11-01 08:29:38 UTC; root
Author: Muhammad Alkhalaf [aut, cre, cph] (ORCID:
    <https://orcid.org/0009-0002-2677-9246>)
Maintainer: Muhammad Alkhalaf <muhammedalkhalaf@gmail.com>