Trait ndarray_stats::Quantile1dExt

source · 
pub trait Quantile1dExt<A, S>where
    S: Data<Elem = A>,{
    fn quantile_mut<I>(&mut self, q: f64) -> Option<A>
    where
        A: Ord + Clone,
        S: DataMut,
        I: Interpolate<A>;
}
Expand description

Quantile methods for 1-D arrays.

Required Methods

Return the qth quantile of the data.

q needs to be a float between 0 and 1, bounds included. The qth quantile for a 1-dimensional array of length N is defined as the element that would be indexed as (N-1)q if the array were to be sorted in increasing order. If (N-1)q is not an integer the desired quantile lies between two data points: we return the lower, nearest, higher or interpolated value depending on the type Interpolate bound I.

Some examples:

  • q=0. returns the minimum;
  • q=0.5 returns the median;
  • q=1. returns the maximum. (q=0 and q=1 are considered improper quantiles)

The array is shuffled in place in order to produce the required quantile without allocating a copy. No assumptions should be made on the ordering of the array elements after this computation.

Complexity (quickselect):

  • average case: O(m);
  • worst case: O(m^2); where m is the number of elements in the array.

Returns None if the array is empty.

Panics if q is not between 0. and 1. (inclusive).

Implementations on Foreign Types

Implementors