How to index an entire 1d array from a 2d array?

[TrevorSatori]

Sorry if this is noobie, but I have been stuck on this for hours. In the docs it makes very clear how to index a specific value from a 2d array arr[[0,1]] = 5, but how would I replace a 1d array (row) inside a 2d array?

I believe it should look something like this.

let mut x: Array2 = Array::zeros((10 , 5));

x[0] += [0,0,0,0,0];

please help.

[jturner314]

I'd suggest reading the Slicing and Subviews docs. The ndarray for NumPy users guide may also be of interest.

Here's some sample code for your specific question:

use ndarray::prelude::*;
use std::ops::AddAssign;

fn main() {
    let mut x: Array2<i32> = Array::zeros((10, 5));
    
    // The examples below use `.row_mut()`. Other options include
    // `.slice_mut()` and `.index_axis_mut()`.
    
    // Assign a row.
    x.row_mut(0).assign(&aview1(&[0,0,0,0,0]));
    
    // Fill all elements of a row with the same value.
    x.row_mut(0).fill(0);
    
    // Add to a row in-place (+= operation). Note the `use std::ops::AddAssign` above.
    x.row_mut(0).add_assign(&aview1(&[0,0,0,0,0]));
}

(Playground)

[TrevorSatori]

Thanks so much for this.