india: Tools for influence diagnostics in statistical models

Set of routines for influence diagnostics by using case-deletion in ordinary least squares, nonlinear regression, ridge estimation and LAD regression.

Resources

Version 0.1-5 of india can be found at the CRAN package repository:

• india_0.1-5.tar.gz - Package sources
• india_0.1-5.zip - Windows binaries (R-release)
• india_0.1-5.tgz - MacOS binaries (R-release, arm64)
• india_0.1-5.tgz - MacOS binaries (R-release, x86_64)

Reference Manual

• PDF manual | HTML manual

Features

Lastest release (Sep 14, 2026) of india package have implemented the following influence measures for objects of class lm, nls, lad, ols and ridge, provided by stats, L1pack and fastmatrix, respectively.

• Cook's distances.
• Leverages (or hatvalues).
• Likelihood displacement.
• QQ-plot with simulated envelope for residuals.
• Randomized quantile residuals.
• Relative change in the condition number.

Our plan in the near future is the implementation of functions to handle:

• General models commonly used in Statistics.
• Procedures for assessing the local influence considering several perturbation schemes.

Installation instructions

To install india (version 0.1-5) from CRAN, start R and enter:

install.packages("india")

Or install it from its GitHub repository. First install the devtools package.

install.packages("devtools")

Then install india using the install_github function in devtools

library(devtools)
install_github("faosorios/india", subdir = "pkg")

Alternatively, you can download the source as a tarball (.tar.gz file). Unpack this file (thereby creating a directory named, india) and install the package source by executing (at the console prompt)

R CMD INSTALL india

Next, you can load the package by using the command: library(india)

Providing Feedback

Please report any bugs/suggestions/improvements to Felipe Osorio. If you find these routines useful or not then please let me know. Also, acknowledgement of the use of the routines is appreciated.

To cite the fastmatrix package in publications use:

citation("india")

To cite india in publications use:

  Osorio, F. (2026). india: Influence Diagnostics in Statistical
  Models. R package version 0.1-5. URL:
  https://github.com/faosorios/india

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {india: Influence Diagnostics in Statistical Models},
    author = {F. Osorio},
    year = {2026},
    note = {R package version 0.1-5},
    url = {https://github.com/faosorios/india},
  }

Technical notes

• Computing the leverage constants for LAD regression [PDF (285 Kb)]

Papers using india

• Osorio, F. (2026). On the mean-shift outlier model for LAD regression. Journal of Statistical Computation and Simulation, doi: 10.1080/00949655.2026.2716387
• Ogueda, A., Osorio, F. (2025). Influence diagnostics for ridge regression using the Kullback-Leibler divergence. Statistical Papers 66, 85.

About the Author

Felipe Osorio is an applied statistician and creator of several R packages

• Webpage: faosorios.github.io