ci_chisq_ncp: CI for the NCP of the Chi-Squared Distribution

In confintr: Confidence Intervals

CI for the NCP of the Chi-Squared Distribution

Description

This function calculates CIs for the non-centrality parameter (NCP) of the \chi^2-distribution. A positive lower (1 - \alpha) \cdot 100\%-confidence limit for the NCP goes hand-in-hand with a significant association test at level \alpha.

Usage

ci_chisq_ncp(
  x,
  probs = c(0.025, 0.975),
  correct = TRUE,
  type = c("chi-squared", "bootstrap"),
  boot_type = c("bca", "perc", "norm", "basic"),
  R = 9999L,
  seed = NULL,
  ...
)

Arguments

x	The result of stats::chisq.test(), a matrix/table of counts, or a data.frame with exactly two columns representing the two variables.
probs	Lower and upper probabilities, by default c(0.025, 0.975).
correct	Should Yates continuity correction be applied to the 2x2 case? The default is TRUE (also used in the bootstrap), which differs from ci_cramersv().
type	Type of CI. One of "chi-squared" (default) or "bootstrap".
boot_type	Type of bootstrap CI. Only used for type = "bootstrap".
R	The number of bootstrap resamples. Only used for type = "bootstrap".
seed	An integer random seed. Only used for type = "bootstrap".
...	Further arguments passed to boot::boot().

Details

By default, CIs are computed by Chi-squared test inversion. This can be unreliable for very large test statistics. The default bootstrap type is "bca".

Value

An object of class "cint", see ci_mean() for details.

References

Smithson, M. (2003). Confidence intervals. Series: Quantitative Applications in the Social Sciences. New York, NY: Sage Publications.

See Also

ci_cramersv()

Examples

ci_chisq_ncp(mtcars[c("am", "vs")])
ci_chisq_ncp(mtcars[c("am", "vs")], type = "bootstrap", R = 999)  # Use larger R

confintr documentation built on June 7, 2023, 6:24 p.m.