Package: tptest
Type: Package
Title: Universal Turning Point and Inflection Point Tests
Version: 1.0.3
Date: 2026-03-07
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
RoxygenNote: 7.3.3
Depends: R (>= 4.0.0)
Imports: stats, graphics
Suggests: testthat (>= 3.0.0), knitr, rmarkdown, lmtest, sandwich, plm,
        quantreg
NeedsCompilation: no
Packaged: 2026-04-02 15:26:14 UTC; SYSTEM
Author: Muhammad Alkhalaf [aut, cre, cph] (ORCID:
    <https://orcid.org/0009-0002-2677-9246>)
Maintainer: Muhammad Alkhalaf <muhammedalkhalaf@gmail.com>
Repository: CRAN
Date/Publication: 2026-04-09 08:20:02 UTC
Built: R 4.6.0; ; 2026-04-25 22:53:51 UTC; unix
