Way to map an array into an array with an extra dimension.

[Kwonunn]

Let's say I have some function which takes a scalar argument and uses it to produce an array like so:

fn compute(x: u32) -> Array1<u32> {
    // ...
}

If I map this function onto an Array of u32, I get an Array of Arrays:

let a = arr1(&[1, 2, 3, 4]); // a has type Array1<u32>
let b = a.map(|x| compute(x)); // b has type Array1<Array1<u32>>

Is there a way to map that creates a higher-dimension array? For example:

let c = a.hypothetical_map(|x| compute(x)); // c has type Array2<u32>

[nilgoyette]

It depends how you want to use the array a. Is c dimension based on a?

• You may want to build a 2d array first, then use Zip::from(&mut arr).and(&a)
• You could use from_shape_fn to initialize the values from the indices.
• There are other tricks, but I don't know exactly what you need, so the best I can do is to tell you to read section about "Constructor Methods for Owned Arrays", which is immensely useful if you're going to work with ndarray.

[Kwonunn]

I solved my issue using the Zip method. It might still be nice to have some way of doing this that doesn't require allocating and zero-ing a whole array beforehand, but I think my question has been answered.

Thank you!