Skewness

Functions to compute skewness.

Usage

skewness(x, ...)

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

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

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

# S3 method for 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.

Value

a numeric value or vector with attribute "method" indicating the method.

See also

kurtosis

Examples

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