Provides a pipe-friendly framework to performs Shapiro-Wilk test of normality. Support grouped data and multiple variables for multivariate normality tests. Wrapper around the R base function shapiro.test(). Can handle grouped data.

shapiro_test(data, ..., vars = NULL)

mshapiro_test(data)

Arguments

data

a data frame. Columns are variables.

...

One or more unquoted expressions (or variable names) separated by commas. Used to select a variable of interest.

vars

optional character vector containing variable names. Ignored when dot vars are specified.

Value

a data frame containing the value of the Shapiro-Wilk statistic and the corresponding p.value.

Functions

  • shapiro_test: univariate Shapiro-Wilk normality test

  • mshapiro_test: multivariate Shapiro-Wilk normality test. This is a modified copy of the mshapiro.test() function of the package mvnormtest, for internal convenience.

Examples

# Shapiro Wilk normality test for one variable iris %>% shapiro_test(Sepal.Length)
#> # A tibble: 1 x 3 #> variable statistic p #> <chr> <dbl> <dbl> #> 1 Sepal.Length 0.976 0.0102
# Shapiro Wilk normality test for two variables iris %>% shapiro_test(Sepal.Length, Petal.Width)
#> # A tibble: 2 x 3 #> variable statistic p #> <chr> <dbl> <dbl> #> 1 Petal.Width 0.902 0.0000000168 #> 2 Sepal.Length 0.976 0.0102
# Multivariate normality test mshapiro_test(iris[, 1:3])
#> # A tibble: 1 x 2 #> statistic p.value #> <dbl> <dbl> #> 1 0.991 0.443