Performs the Jarque-Bera chi-squared test, a moment-based omnibus test for assessing normality.
Usage
Jarque_Bera_test(
x,
alpha = 0.05,
alternative = c("two.sided", "less", "greater"),
silent = FALSE,
summary = TRUE
)Arguments
- x
Numeric vector. Must contain at least 20 observations.
- alpha
Numeric (default: 0.05). Significance level for hypothesis testing. Must be between 0 and 1.
- alternative
Character (default:
"two.sided"). Specifies the alternative hypothesis. Available options arec("two.sided", "less", "greater"). This argument applies only to the skewness and kurtosis components and does not affect the Jarque-Bera omnibus test statistic itself.- silent
Logical (default:
FALSE). IfFALSE, results are printed to the console.- summary
Logical (default: TRUE). Produce a summary table.
Details
The test evaluates the null hypothesis that the data are drawn from a normal distribution by combining standardized measures of skewness and kurtosis into a single chi-squared test statistic.
References
Jarque, C.M., Bera, A.K., 1987. A Test for Normality of Observations and Regression Residuals. Int. Stat. Rev. 55, 163–172. https://doi.org/10.2307/1403192
Examples
out <- Jarque_Bera_test(rnorm(50))
#>
#> ------------------------------------
#> Jarque-Bera (JB) normality test
#>
#> Alternative: two.sided
#>
#> Skewness = -0.388 ; p-value = 0.22048
#> Kurtosis = 2.9852 ; p-value = 0.97944
#>
#> Statistic (JB) = 1.255
#> p-value = 0.53391
#> ------------------------------------
print(out$summary)
#> alpha statistic pval signif standard_value
#> skewness (b1) 0.05 -0.3880089 0.2204761 ns -1.22526306
#> kurtosis (b2) 0.05 2.9852133 0.9794439 ns -0.02576604
#> Jarque-Bera (JB) 0.05 1.2550463 0.5339126 ns 1.25504633
#> critical_value SE CI_lower CI_upper N AVG
#> skewness (b1) 1.959964 0.3166739 -1.008678 0.2326606 50 0.1411339
#> kurtosis (b2) 1.959964 0.5738823 1.860425 4.1100021 50 0.1411339
#> Jarque-Bera (JB) 5.991465 NA NA NA 50 0.1411339
#> MED MIN MAX SD
#> skewness (b1) 0.243049 -2.612334 2.12685 0.9878414
#> kurtosis (b2) 0.243049 -2.612334 2.12685 0.9878414
#> Jarque-Bera (JB) 0.243049 -2.612334 2.12685 0.9878414