rust ndarray

sample.rs

// cargo-deps: serde, serde_derive, serde_yaml, ndarray
extern crate ndarray;
extern crate serde;
use ndarray::array;
use ndarray::prelude::*;
use ndarray::Array;
use ndarray::Array1;

fn main() {
    let arr1: Array1<f64> = array![1.0, 2.0, 3.0, 4.0];
    let arr2: Array1<f64> = array![5.0, 6.0, 7.0, 8.0];
    let mut arr_sum1: Array1<f64> = Array::zeros(4);
    println!("{}", &arr_sum1);
    arr_sum1.slice(s![0..2]) = &arr1.slice(s![1..3]) + &arr2.slice(s![2..4]);
}

出てくるエラーは次の通り。

error[E0308]: mismatched types
--> code_check.rs:28:32
|
28 | arr_sum1.slice(s![0..2]) = &arr1.slice(s![1..3]) + &arr2.slice(s![2..4]);
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected struct ndarray::ViewRepr, found struct ndarray::OwnedRepr
|
= note: expected struct ndarray::ArrayBase<ndarray::ViewRepr<&f64>, _>
found struct ndarray::ArrayBase<ndarray::OwnedRepr<f64>, _>

error[E0070]: invalid left-hand side expression
--> code_check.rs:28:5
|
28 | arr_sum1.slice(s![0..2]) = &arr1.slice(s![1..3]) + &arr2.slice(s![2..4]);
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ left-hand of expression not valid