This method performs a Chi-square goodness-of-fit-test (GOF) either on a numeric vector against probabilities, or a Goodness-of-fit test for glm-objects for binary data.

chisq_gof(x, prob = NULL, weights = NULL)

Arguments

x

Numeric vector, or a glm-object.

prob

Vector of probabilities (indicating the population probabilities) of the same length as x's amount of categories / factor levels. Use nrow(table(x)) to determine the amount of necessary values for prob. Only used, when x is a vector, and not a glm-object.

weights

Vector with weights, used to weight x.

Value

For vectors, returns the object of the computed chisq.test.

For glm-objects, an object of class chisq_gof with following values:

  • p.value the p-value for the goodness-of-fit test

  • z.score the standardized z-score for the goodness-of-fit test

  • RSS the residual sums of squares term

  • X2 the pearson chi-squared statistic

Note

For vectors, this function is a convenient function for the chisq.test, performing goodness-of-fit test.

For glm-objects, this function performs a goodness-of-fit test based on the X2GOFtest function of the binomTools package. A well-fitting model shows no significant difference between the model and the observed data, i.e. the reported p-values should be greater than 0.05.

Examples

data(efc) # differing from population chisq_gof(efc$e42dep, c(0.3,0.2,0.22,0.28))
#> #> Chi-squared test for given probabilities #> #> data: dummy #> X-squared = 234.76, df = 3, p-value < 2.2e-16 #>
# equal to population chisq_gof(efc$e42dep, prop.table(table(efc$e42dep)))
#> #> Chi-squared test for given probabilities #> #> data: dummy #> X-squared = 0, df = 3, p-value = 1 #>
# goodness-of-fit test for logistic regression efc$services <- ifelse(efc$tot_sc_e > 0, 1, 0) fit <- glm(services ~ neg_c_7 + c161sex + e42dep, data = efc, family = binomial(link = "logit")) chisq_gof(fit)
#> $p.value #> [1] 0.0002229002 #> #> $z.score #> [1] 3.69154 #> #> $RSS #> [1] 1.139646 #> #> $X2 #> [1] 889.9409 #> #> attr(,"class") #> [1] "chi2gof"