FunChisq: Model-Free Functional Chi-Squared and Exact Tests

Statistical hypothesis testing methods for inferring model-free functional dependency using asymptotic chi-squared or exact distributions. Functional test statistics are asymmetric and functionally optimal, unique from other related statistics. Tests in this package reveal evidence for causality based on the causality-by-functionality principle. They include asymptotic functional chi-squared tests ('Zhang & Song' 2013) <arXiv:1311.2707> and an exact functional test ('Zhong & Song' 2019) <doi:10.1109/TCBB.2018.2809743>. The normalized functional chi-squared test was used by Best Performer 'NMSUSongLab' in HPN-DREAM (DREAM8) Breast Cancer Network Inference Challenges ('Hill et al' 2016) <doi:10.1038/nmeth.3773>. A function index ('Zhong & Song' in press) ('Kumar et al' 2018) <doi:10.1109/BIBM.2018.8621502> derived from the functional test statistic offers a new effect size measure for the strength of functional dependency, a better alternative to conditional entropy in many aspects. For continuous data, these tests offer an advantage over regression analysis when a parametric functional form cannot be assumed; for categorical data, they provide a novel means to assess directional dependency not possible with symmetrical Pearson's chi-squared or Fisher's exact tests.

Depends: R (≥ 3.0.0)
Imports: Rcpp, stats
LinkingTo: BH, Rcpp
Suggests: Ckmeans.1d.dp, testthat, knitr, rmarkdown
Published: 2019-09-24
Author: Yang Zhang [aut], Hua Zhong ORCID iD [aut], Hien Nguyen ORCID iD [aut], Ruby Sharma [aut], Sajal Kumar [aut], Joe Song ORCID iD [aut, cre]
Maintainer: Joe Song <joemsong at>
License: LGPL (≥ 3)
NeedsCompilation: yes
Citation: FunChisq citation info
Materials: README NEWS
CRAN checks: FunChisq results


Reference manual: FunChisq.pdf
Vignettes: Using the exact functional test
Measuring functional dependency model-free
Examples of discrete patterns
Package source: FunChisq_2.4.9.1.tar.gz
Windows binaries: r-devel:, r-release:, r-oldrel:
OS X binaries: r-release: FunChisq_2.4.9.1.tgz, r-oldrel: FunChisq_2.4.9.1.tgz
Old sources: FunChisq archive


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