Why do functions of trait Statistics take ownership on the dataset and not immutable reference ?

[DvxBellorvm]

Hello

This is a question I have been wondering for a while: why all the functions in the statistics::Statistics trait take self and not &self ?
I often have the use case where I need to compute several statistics on the same dataset, like for example:

use statrs::statistics::Statistics;

fn main() {
    let dataset = vec![0., 1., 2., 3., 4., 5.];
    let mean = dataset.mean();
    let variance = dataset.variance();
}

but I cannot do so because mean(self) function takes ownership on the dataset. The only solution I see is to clone the dataset, which in my use case is usually not wanted.
Naïvely, if I had to implement a mean() function, I would only need an immutable reference on the dataset to do so, so I am wondering if there is a specific reason for this particular design choice, and could it change in the future ?

[YeungOnion]

We could certainly change this so that only the rank/order related statistics have the ownership signature. We could also use an iterator trait bound, are you able to make the change?

[HuStmpHrrr]

the same question. it doesn't make sense to take the ownership of the data structure at all.