waldchisq: Wald-type chi-squared test
In corncob: Count Regression for Correlated Observations with the Beta-Binomial

waldchisq

R Documentation

Wald-type chi-squared test

Description

Wald-type chi-squared test

Usage

waldchisq(
  mod,
  mod_null = NULL,
  restrictions = NULL,
  restrictions.phi = NULL,
  contrasts_DA = NULL,
  contrasts_DV = NULL,
  robust = FALSE
)

Arguments

`mod`	an object of class `bbdml`
`mod_null`	Optional. An object of class `bbdml`, should be nested within `mod`. If not included, need to include `restrictions` or `restrictions.phi`.
`restrictions`	Optional. Defaults to `NULL`. Numeric vector indicating the parameters associated with the abundance to test, or character vector with name of variable to test. Note that `1` is the intercept associated with the abundance.
`restrictions.phi`	Optional. Defaults to `NULL`. Numeric vector indicating the parameters associated with the dispersion to test, or character vector with name of variable to test. Note that `1` is the intercept associated with the dispersion.
`contrasts_DA`	List. Optional. Constructs a contrast matrix. List elements should be characters specifying contrasts in the parameters within `formula`. Note that this is only available with `"Wald"` value for `test`.
`contrasts_DV`	List. Optional. Constructs a contrast matrix. List elements should be characters specifying contrasts in the parameters within `phi.formula`. Note that this is only available with `"Wald"` value for `test`.
`robust`	Should robust standard errors be used? If not, model-based standard arras are used. Logical, defaults to `FALSE`.

Value

Matrix with wald test statistics and p-values. Only performs univariate tests.

P-value from Wald test.

Examples

data(soil_phylum_small_otu1)
mod1 <- bbdml(formula = cbind(W, M - W) ~ DayAmdmt,
phi.formula = ~ DayAmdmt,
data = soil_phylum_small_otu1)

mod2 <- bbdml(formula = cbind(W, M - W) ~ 1,
phi.formula = ~ 1,
data = soil_phylum_small_otu1)

# Example using mod_null
waldchisq(mod = mod1, mod_null = mod2)
waldchisq(mod = mod1, mod_null = mod2, robust = TRUE)

# Example using restrictions and restrictions.phi
waldchisq(mod = mod1, restrictions = 2, restrictions.phi = 2)
waldchisq(mod = mod1, restrictions = "DayAmdmt", restrictions.phi = "DayAmdmt")
waldchisq(mod = mod1, restrictions = 2, restrictions.phi = "DayAmdmt")
waldchisq(mod = mod1, restrictions = 2, restrictions.phi = 2, robust = TRUE)

corncob documentation built on May 29, 2024, 7:15 a.m.