Skip to content

tptest

Universal Turning Point and Inflection Point Tests

v1.0.3 · Apr 9, 2026 · GPL-3

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>.

Downloads

CRAN

416

Last 30 days

9684th

1.2K

Last 90 days

1.2K

Last year

Trend: -7.6% (30d vs prior 30d)

r2u CRAN

7

Last 30 days

21

Last 90 days

21

Last year

Trend: -50% (30d vs prior 30d)

autoCRAN

1

Last 7 days

3

Last 30 days

0

All-time

autoCRAN-only: this name is served only by autoCRAN, so the count is exact.

CRAN Check Status

13 OK
Show all 13 flavors
Flavor Status
r-devel-linux-x86_64-debian-clang OK
r-devel-linux-x86_64-debian-gcc OK
r-devel-linux-x86_64-fedora-clang OK
r-devel-linux-x86_64-fedora-gcc OK
r-devel-windows-x86_64 OK
r-oldrel-macos-arm64 OK
r-oldrel-macos-x86_64 OK
r-oldrel-windows-x86_64 OK
r-patched-linux-x86_64 OK
r-release-linux-x86_64 OK
r-release-macos-arm64 OK
r-release-macos-x86_64 OK
r-release-windows-x86_64 OK

Check History

OK 13 OK · 0 NOTE · 0 WARNING · 0 ERROR · 0 FAILURE Jun 9, 2026
NOTE 12 OK · 1 NOTE · 0 WARNING · 0 ERROR · 0 FAILURE Jun 8, 2026
NOTE r-devel-linux-x86_64-debian-gcc

dependencies in R code

Fatal error: cannot create 'R_TempDir'
OK 6 OK · 0 NOTE · 0 WARNING · 0 ERROR · 0 FAILURE Apr 10, 2026

Version History

1 tracked
new 1.0.3 Apr 9, 2026