Skewness

Functions to compute skewness.

Usage

skewness(x, ...)

# Default S3 method
skewness(x, na.rm = FALSE, method = c("moment", "fisher"), ...)

# S3 method for class 'data.frame'
skewness(x, na.rm = FALSE, method = c("moment", "fisher"), ...)

# S3 method for class 'POSIXct'
skewness(x, ...)

# S3 method for class 'POSIXlt'
skewness(x, ...)

Arguments

x

a numeric vector or object.

na.rm

a logical. Should missing values be removed?

method

a character string, the method of computation, see section ‘Detaials’.

...

arguments to be passed.

Details

Argument method can be one of "moment" or "fisher". The "moment" method is based on the definitions of skewness for distributions and this should be used when resampling (bootstrap or jackknife). The "fisher" method correspond to the usual "unbiased" definition of sample variance, although in the case of skewness exact unbiasedness is not possible.

The data frame method computes the skewness of each column.

Value

a numeric value or vector with attribute "method" indicating the method. For the data frame method the values are named using the columns names.

See also

kurtosis

Examples

r = rnorm(100)
mean(r)
#> [1] 0.02388186
var(r)
#> [1] 1.000822
   
skewness(r)  
#> [1] 0.07497603
#> attr(,"method")
#> [1] "moment"