pub trait MomentSeries: SeriesSealed {
// Provided methods
fn skew(&self, bias: bool) -> Result<Option<f64>, PolarsError> { ... }
fn kurtosis(
&self,
fisher: bool,
bias: bool,
) -> Result<Option<f64>, PolarsError> { ... }
}
Provided Methods§
Sourcefn skew(&self, bias: bool) -> Result<Option<f64>, PolarsError>
fn skew(&self, bias: bool) -> Result<Option<f64>, PolarsError>
Compute the sample skewness of a data set.
For normally distributed data, the skewness should be about zero. For
uni-modal continuous distributions, a skewness value greater than zero means
that there is more weight in the right tail of the distribution. The
function skewtest
can be used to determine if the skewness value
is close enough to zero, statistically speaking.
see: scipy
Sourcefn kurtosis(&self, fisher: bool, bias: bool) -> Result<Option<f64>, PolarsError>
fn kurtosis(&self, fisher: bool, bias: bool) -> Result<Option<f64>, PolarsError>
Compute the kurtosis (Fisher or Pearson) of a dataset.
Kurtosis is the fourth central moment divided by the square of the
variance. If Fisher’s definition is used, then 3.0 is subtracted from
the result to give 0.0 for a normal distribution.
If bias is false
then the kurtosis is calculated using k statistics to
eliminate bias coming from biased moment estimators
see: scipy